GitLab

Docs only, no change to production code.

This removes backticks on "Install depot_tools" to render better in the
table of contents (gitiles strips code-formatted text from TOC) and have
more sensible fragment link anchors. This updates all markdown files
dependent on the link anchor.

Bug: 918221
Test: Upload to gerrit > open file > click "gitiles"
Change-Id: Id8ec00af6a796212bbc6ceebd5c3d20ca80da920
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1656375
Auto-Submit: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Paul Miller <paulmiller@chromium.org>
Reviewed-by: Paul Miller <paulmiller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#668549}