Add internal links (i.e. links to anchor) as the version of Markdown used
by gitiles generate anchors for each heading automatically.

Use ``` syntax to introduce the blocs of code so that we can specify the
syntax to use for color highlighting (shell, json, ...).

Convert enumerated list (1-, 2-, ...) to the proper format to get a nice
HTML enumerated list (i.e. 1., 2., ...).

Remove superfluous '\' that appeared in the output and always format file
names as code using `filename`.

BUG=None

Review URL: https://codereview.chromium.org/1757833002

Cr-Commit-Position: refs/heads/master@{#378723}