docs: Add more information to the HTML sidebar

Add a new sidebar template that creates a more RTD-like "fisheye" view of
the current place in the document hierarchy.  It is far from ideal, but
some readers may find it better for navigating through the documentation as
a whole.

Add some CSS trickery as well to make the table of contents less intrusive
when viewing the pages on a small screen.

Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
Reviewed-by: David Gow <davidgow@google.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Jonathan Corbet 2023-01-19 17:03:05 -07:00
commit c404f5d4f0
3 changed files with 66 additions and 3 deletions