Relevant change is in make_docs.sh, all other files were generated.

R=iannucci@chromium.org

Changes:
* upgrade to latest asciidoc, ansi2html and git
* disable interactive git editor (happens during rebase)
* minor tweaks
Change-Id: Ie4b19aa12b8a76826f66e3088c985b99e55164c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3000882Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>