Enhance the hooks document generation process

[ianlin]

Context

Follow-up from #1573 (comment), which it added a script to generate the hooks document and put it in src/Hooks/README.md.

User story

• As a developer, I'd like the hooks document to be auto generated every time I add or remove the hooks (actions/filters).
• As a developer I'd like the hooks document has a simple description under each hook.

Describe the solution you'd like

For auto generate hooks document:

1. Add Git pre-commit hooks to check if the current staged changes have code difference with keywords do_action, add_action, apply_filter, and add_filter.
   • Maybe run git diff --cached --word-diff -U1 | grep -E 'add_action|do_action|add_filter|apply_filter'
2. If yes, run the script to regenerate hooks document, then commit the changes (without the newly generated doc).
3. Run git add and git commit again to commit the generated doc.

For adding descriptions under each hoook:

1. Write down the hooks we used using PHPDoc.
2. See if we can extend PHPDoc for having the custom tags in order to auto generate it.
3. Also see if we can extend PHPDoc to generate the doc in markdown format and put it in src/Hooks/README.md.
   • Like how woocommerce-grow-tracking-jsdoc did.

[puntope]

As a developer, I'd like the hooks document to be auto generated every time I add or remove the hooks (actions/filters).

This part can be considered as done with #2060