DOC: Added link to file bug against doc
DOC: Added link to file bug against doc

Reporting an issue with documentation is now one click away. Added a
link in the header.

BUG=

Review URL: https://codereview.chromium.org/803933007

nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra