[Security Solution][Elastic AI Assistant] Updates ESQL Knowledge Base…

… docs to latest (elastic#169593)

## Summary

In preparation for the final `8.11` BC, this PR updates the Assistant
ESQL Knowledge Base docs to match that of the latest [Elasticsearch ESQL
documentation](https://github.com/elastic/elasticsearch/tree/main/docs/reference/esql)
and [language
files](https://github.com/elastic/elasticsearch/tree/f883dd98566c1f8ffa34779c9949eaeb27596014/x-pack/plugin/esql/src/main/antlr).


## Update process

To update, I deleted the
`x-pack/plugins/elastic_assistant/server/knowledge_base/documentation`
folder contents, then copied the latest [Elasticsearch ESQL
documentation](https://github.com/elastic/elasticsearch/tree/main/docs/reference/esql)
files over. Then ran the below script from that directory via terminal
to rename all files/directories from `kebab-case` to `snake_case` as
required by the Kibana repo:

> find . -depth -name '*-*' -exec bash -c 'for f; do base=${f##*/}; mv
-- "$f" "${f%/*}/${base//-/_}"; done' bash {} +


For the language files, I checked those manually and copied over the
entire file contents since there are only 4.

When we do the next update, (and confirm these raw `asciidocs` are the
best format), I will create a single script that can be run for
maintenance purposes.

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_processing_commands.asciidoc → x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_commands.asciidoc

@@ -1,10 +1,28 @@
-[[esql-processing-commands]]
-== {esql} processing commands
+[[esql-commands]]
+=== {esql} commands
 
 ++++
-<titleabbrev>Processing commands</titleabbrev>
+<titleabbrev>Commands</titleabbrev>
 ++++
 
+// tag::source_commands[]
+==== Source commands
+
+An {esql} source command produces a table, typically with data from {es}. An {esql} query must start with a source command.
+
+image::images/esql/source-command.svg[A source command producing a table from {es},align="center"]
+
+{esql} supports these source commands:
+
+* <<esql-from>>
+* <<esql-row>>
+* <<esql-show>>
+
+// end::source_command[]
+
+// tag::proc_commands[]
+==== Processing commands
+
 {esql} processing commands change an input table by adding, removing, or changing
 rows and columns.
 
@@ -25,6 +43,12 @@ image::images/esql/processing-command.svg[A processing command changing an input
 * <<esql-stats-by>>
 * <<esql-where>>
 
+// end::proc_command[]
+
+include::source-commands/from.asciidoc[]
+include::source-commands/row.asciidoc[]
+include::source-commands/show.asciidoc[]
+
 include::processing-commands/dissect.asciidoc[]
 include::processing-commands/drop.asciidoc[]
 include::processing-commands/enrich.asciidoc[]

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_enrich_data.asciidoc

@@ -0,0 +1,126 @@
+[[esql-enrich-data]]
+=== Enrich data
+
+++++
+<titleabbrev>Enrich data</titleabbrev>
+++++
+
+You can use {esql}'s <<esql-enrich>> processing command to enrich a table with
+data from indices in {es}.
+
+For example, you can use `ENRICH` to:
+
+* Identify web services or vendors based on known IP addresses
+* Add product information to retail orders based on product IDs
+* Supplement contact information based on an email address
+
+[[esql-how-enrich-works]]
+==== How the `ENRICH` command works
+
+The `ENRICH` command adds new columns to a table, with data from {es} indices.
+It requires a few special components:
+
+image::images/esql/esql-enrich.png[align="center"]
+
+[[esql-enrich-policy]]
+Enrich policy::
++
+--
+A set of configuration options used to add the right enrich data to the input
+table.
+
+An enrich policy contains:
+
+include::../ingest/enrich.asciidoc[tag=enrich-policy-fields]
+
+After <<esql-create-enrich-policy,creating a policy>>, it must be
+<<esql-execute-enrich-policy,executed>> before it can be used. Executing an
+enrich policy uses data from the policy's source indices to create a streamlined
+system index called the _enrich index_. The `ENRICH` command uses this index to
+match and enrich an input table.
+--
+
+[[esql-source-index]]
+Source index::
+An index which stores enrich data that the `ENRICH` command can add to input
+tables. You can create and manage these indices just like a regular {es} index.
+You can use multiple source indices in an enrich policy. You also can use the
+same source index in multiple enrich policies.
+
+[[esql-enrich-index]]
+Enrich index::
++
+--
+A special system index tied to a specific enrich policy.
+
+Directly matching rows from input tables to documents in source indices could be
+slow and resource intensive. To speed things up, the `ENRICH` command uses an
+enrich index.
+
+include::../ingest/enrich.asciidoc[tag=enrich-index]
+--
+
+[[esql-set-up-enrich-policy]]
+==== Set up an enrich policy
+
+To start using `ENRICH`, follow these steps:
+
+. Check the <<enrich-prereqs, prerequisites>>.
+. <<esql-create-enrich-source-index>>.
+. <<esql-create-enrich-policy>>.
+. <<esql-execute-enrich-policy>>.
+. <<esql-use-enrich>>
+
+Once you have enrich policies set up, you can <<esql-update-enrich-data,update
+your enrich data>> and <<esql-update-enrich-policies, update your enrich
+policies>>.
+
+[IMPORTANT]
+====
+The `ENRICH` command performs several operations and may impact the speed of
+your query.
+====
+
+[[esql-enrich-prereqs]]
+==== Prerequisites
+
+include::{es-repo-dir}/ingest/apis/enrich/put-enrich-policy.asciidoc[tag=enrich-policy-api-prereqs]
+
+[[esql-create-enrich-source-index]]
+==== Add enrich data
+
+include::../ingest/enrich.asciidoc[tag=create-enrich-source-index]
+
+[[esql-create-enrich-policy]]
+==== Create an enrich policy
+
+include::../ingest/enrich.asciidoc[tag=create-enrich-policy]
+
+[[esql-execute-enrich-policy]]
+==== Execute the enrich policy
+
+include::../ingest/enrich.asciidoc[tag=execute-enrich-policy1]
+
+image::images/esql/esql-enrich-policy.png[align="center"]
+
+include::../ingest/enrich.asciidoc[tag=execute-enrich-policy2]
+
+[[esql-use-enrich]]
+==== Use the enrich policy
+
+After the policy has been executed, you can use the <<esql-enrich,`ENRICH`
+command>> to enrich your data.
+
+image::images/esql/esql-enrich-command.png[align="center",width=50%]
+
+include::processing-commands/enrich.asciidoc[tag=examples]
+
+[[esql-update-enrich-data]]
+==== Update an enrich index
+
+include::{es-repo-dir}/ingest/apis/enrich/execute-enrich-policy.asciidoc[tag=update-enrich-index]
+
+[[esql-update-enrich-policies]]
+==== Update an enrich policy
+
+include::../ingest/enrich.asciidoc[tag=update-enrich-policy]

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_functions.asciidoc

@@ -26,16 +26,17 @@ these functions:
 * <<esql-date_parse>>
 * <<esql-date_trunc>>
 * <<esql-e>>
+* <<esql-ends_with>>
 * <<esql-floor>>
 * <<esql-greatest>>
 * <<esql-is_finite>>
 * <<esql-is_infinite>>
 * <<esql-is_nan>>
 * <<esql-least>>
+* <<esql-left>>
 * <<esql-length>>
 * <<esql-log10>>
 * <<esql-ltrim>>
-* <<esql-rtrim>>
 * <<esql-mv_avg>>
 * <<esql-mv_concat>>
 * <<esql-mv_count>>
@@ -47,13 +48,15 @@ these functions:
 * <<esql-now>>
 * <<esql-pi>>
 * <<esql-pow>>
+* <<esql-replace>>
+* <<esql-right>>
 * <<esql-round>>
+* <<esql-rtrim>>
 * <<esql-sin>>
 * <<esql-sinh>>
 * <<esql-split>>
 * <<esql-starts_with>>
 * <<esql-substring>>
-* <<esql-left>>
 * <<esql-tan>>
 * <<esql-tanh>>
 * <<esql-tau>>
@@ -88,16 +91,17 @@ include::functions/date_format.asciidoc[]
 include::functions/date_parse.asciidoc[]
 include::functions/date_trunc.asciidoc[]
 include::functions/e.asciidoc[]
+include::functions/ends_with.asciidoc[]
 include::functions/floor.asciidoc[]
 include::functions/greatest.asciidoc[]
 include::functions/is_finite.asciidoc[]
 include::functions/is_infinite.asciidoc[]
 include::functions/is_nan.asciidoc[]
 include::functions/least.asciidoc[]
+include::functions/left.asciidoc[]
 include::functions/length.asciidoc[]
 include::functions/log10.asciidoc[]
 include::functions/ltrim.asciidoc[]
-include::functions/rtrim.asciidoc[]
 include::functions/mv_avg.asciidoc[]
 include::functions/mv_concat.asciidoc[]
 include::functions/mv_count.asciidoc[]
@@ -109,14 +113,16 @@ include::functions/mv_sum.asciidoc[]
 include::functions/now.asciidoc[]
 include::functions/pi.asciidoc[]
 include::functions/pow.asciidoc[]
+include::functions/replace.asciidoc[]
+include::functions/right.asciidoc[]
 include::functions/round.asciidoc[]
+include::functions/rtrim.asciidoc[]
 include::functions/sin.asciidoc[]
 include::functions/sinh.asciidoc[]
 include::functions/split.asciidoc[]
 include::functions/sqrt.asciidoc[]
 include::functions/starts_with.asciidoc[]
 include::functions/substring.asciidoc[]
-include::functions/left.asciidoc[]
 include::functions/tan.asciidoc[]
 include::functions/tanh.asciidoc[]
 include::functions/tau.asciidoc[]

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_functions_operators.asciidoc

@@ -0,0 +1,43 @@
+[[esql-functions-operators]]
+=== {esql} functions and operators
+
+++++
+<titleabbrev>Functions and operators</titleabbrev>
+++++
+
+{esql} provides a comprehensive set of functions and operators for working with data.
+The functions are divided into the following categories:
+
+[[esql-functions]]
+<<esql-agg-functions>>::
+include::functions/aggregation-functions.asciidoc[tag=agg_list]
+
+<<esql-math-functions>>::
+include::functions/math-functions.asciidoc[tag=math_list]
+
+<<esql-string-functions>>::
+include::functions/string-functions.asciidoc[tag=string_list]
+
+<<esql-date-time-functions>>::
+include::functions/date-time-functions.asciidoc[tag=date_list]
+
+<<esql-type-conversion-functions>>::
+include::functions/type-conversion-functions.asciidoc[tag=type_list]
+
+<<esql-conditional-functions-and-expressions>>::
+include::functions/conditional-functions-and-expressions.asciidoc[tag=cond_list]
+
+<<esql-mv-functions>>::
+include::functions/mv-functions.asciidoc[tag=mv_list]
+
+<<esql-operators>>::
+include::functions/operators.asciidoc[tag=op_list]
+
+include::functions/aggregation-functions.asciidoc[]
+include::functions/math-functions.asciidoc[]
+include::functions/string-functions.asciidoc[]
+include::functions/date-time-functions.asciidoc[]
+include::functions/type-conversion-functions.asciidoc[]
+include::functions/conditional-functions-and-expressions.asciidoc[]
+include::functions/mv-functions.asciidoc[]
+include::functions/operators.asciidoc[]

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_get_started.asciidoc

@@ -0,0 +1,8 @@
+[[esql-getting-started]]
+== Getting started with {esql}
+
+++++
+<titleabbrev>Getting started</titleabbrev>
+++++
+
+coming::[8.11]

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_kibana.asciidoc

@@ -0,0 +1,15 @@
+[[esql-kibana]]
+== Using {esql} in {kib}
+
+++++
+<titleabbrev>Kibana</titleabbrev>
+++++
+
+
+Use {esql} in Discover to explore a data set. From the data view dropdown,
+select *Try {esql}* to get started.
+
+NOTE: {esql} queries in Discover and Lens are subject to the time range selected
+with the time filter.
+
+

x-pack/plugins/elastic_assistant/server/knowledge_base/esql/documentation/esql_language.asciidoc

@@ -0,0 +1,23 @@
+[[esql-language]]
+== Working with the {esql} language
+
+++++
+<titleabbrev>Working with the {esql} language</titleabbrev>
+++++
+
+Detailed information about the {esql} language:
+
+* <<esql-syntax>>
+* <<esql-commands>>
+* <<esql-functions>>
+* <<esql-multivalued-fields>>
+* <<esql-metadata-fields>>
+* <<esql-enrich-data>>
+
+include::esql-syntax.asciidoc[]
+include::esql-commands.asciidoc[]
+include::esql-functions-operators.asciidoc[]
+include::multivalued-fields.asciidoc[]
+include::metadata-fields.asciidoc[]
+include::esql-enrich-data.asciidoc[]
+