[Test Automation] add go link and correct version

Markdown document updates only.

Change-Id: I8441d8a0ab4f2befdb9d0426a0b73e7f04813e94
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4358986
Auto-Submit: Dana Fried <dfried@chromium.org>
Commit-Queue: Lindsay Pasricha <lindsayw@chromium.org>
Reviewed-by: Lindsay Pasricha <lindsayw@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1121920}

chrome/test/interaction/README.md

@@ -1,12 +1,17 @@
 # Interactive Testing API: "Kombucha"
 
+**[go/kombucha-api](goto.google.com/kombucha-api)**
+
 **Kombucha** is a group of powerful test mix-ins that let you easily and
 concisely write interactive tests.
 
-The current API version is 1.55. All future 1.x versions are guaranteed to
+The current API version is 2.0. All future 2.x versions are guaranteed to
 either be backwards-compatible with existing tests, or the authors will update
 the API calls for you.
 
+This page provides technical documentation. For a cookbook/FAQ/troubleshooting
+guide, see our [Kombucha Playbook](goto.google.com/kombucha-playbook).
+
 [TOC]
 
 ## Getting Started