Autogenerate hooks summary (with Symfony CLI tool)

Done with:
./bin/tools generate:hook-list

- Keep the summary short
- Use a separate "Notes" section for overflow

This way MkDocs will be able to report errors for broken links

Done with:

perl -0777 -i -pe \
's@(?<!!)\[([^\]]*)\]\((?!https?://)(?!mailto:)(/(?:(?:(?:/(?![\)#]))|[^/)#])(?!.md))+)/?(#[^)]*)?\)@[$1]($2.md$3)@gm' \
`find . -name '*.md'`

Remove "additional pages" section from AngularJS intro page

because these pages are already listed in the menu and I think that
listing them in two places will be prone to content errors

CRM-20600 - Add chapters for AngularJS and AssetBuilder