fix errors in GitLab documentation (!2043) · Merge requests · Warren Gifford / sourcegraph · GitLab

Warren Gifford requested to merge clarify-gitlab-docs into master Jan 28, 2019

Created by: sqs

The GitHub and GitLab headings contained " (beta)", which meant that their anchors were #github-beta and #gitlab-beta, but other pages linked to #gitlab.
Certain links from GitLab sections linked to GitHub pages (probably due to an error when copy-pasting).

fix (partially) https://github.com/sourcegraph/sourcegraph/issues/2040