* Refine YAML date regex

This commit does a few changes:

- Introduce a new regex
  - it is a bit off-spec (it allows one-digit months and days in date-only mode)
  - uses named groups
  - avoids group duplication
- parses offset once

Fixes #2538

* Fix nanosecond parsing

* Rename variables for brewity

* Add tests

Closes #2563

* Add feature to disable robots.txt and sitemap.xml from the config file.

Addresses feature request #2248

* Add documentation for no_sitemap & no_robots

* Rename no_robots and no_sitemap into generate_robots_txt and generate_sitemap (default to true)

* fix rustfmt issues

* Change documentation to show defaults

* Update documentation for the fields generate_sitemaps (resp. robots_txt), now that the default is true and false is needed to disable

…2575)

- Some error messages refer to `get_taxonomy_term_by_name` instead of
`get_taxonomy_term`
- If a term cannot be found in a taxonomy, the error message
erroneously pretends that the taxonomy itself is unknown instead of
the term.

Cleanup code by using `Option::is_some_and()` and
`Option::as_deref()` instead of recoding them.

* update docs

* add config option, logic, and tests

* remove config option

…ion) (#2606)

* Fix shortcode/continue-reading parsing with inline HTML (smaller version)

* Remove inline <!-- more -->