This provides custom CSS to override Doxygen’s default font choices.
It uses the Open Sans and Source Code Pro as used on Gitiles and
PolyGerrit.
A slightly-improved Doxygen main page is included as well.
Change-Id: Ib9f7e7d3eef7d3b78231e2dc9430aa8758590773
Reviewed-on: https://chromium-review.googlesource.com/408715
Reviewed-by: Robert Sesek <rsesek@chromium.org>
