☂️ Streamline metadata/config maintenance for documentation

[shreyas-s-rao]

How to categorize this issue?

/area documentation open-source
/kind enhancement task

What would you like to be added:
Avoid maintenance overhead for documentation files in multiple places like docs TOC, mkdocs configuration, docforge manifest (this is hardly changed over time, so it's still not an issue as such), etc.

Task List:

• Until we have automatic generation, update PR template with checklist for adding/updating docs, updating mkdocs, TOC, tests (unrelated to this issue, but still necessary in the PR checklist), etc -> Add checklist for PRs #1253
• Avoid double maintenance overhead for new docs files in mkdocs.yml #1250
• Automatically generate TOC for docs #1251
• Update and correct docs for new features/changes introduced in #988 #1011
• Note blocks that render well on github markdown (> [!NOTE]), do not render well on mkdocs which expects !!! note, and vice versa. Update all docs to use github-native note blocks, and add a replacement step in publish-docs workflow to locally convert them to mkdocs native note blocks before publishing to gh-pages.