index.md: Replace adhoc ToC with a standard mkdocs TOC macro

Instead of manually generated ToC using an external web tool, use a
by-default enabled MkDocs extension which automatically generates it.

https://python-markdown.github.io/extensions/toc/

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I8ecc13c478d220dc9e351c386319d8fc5f646c7a
1 file changed
tree: 47cddd962524b3e29e4fc6fdc6ae7407ca7c0184
  1. docs/
  2. .gitreview
  3. mkdocs.yml
  4. requirements.txt