Add some GitLab instances
Extracted some GitLab instances from
https://wiki.p2pfoundation.net/List_of_Community-Hosted_GitLab_Instances,
https://granite.phys.s.u-tokyo.ac.jp/trac/Lab/ticket/7, and my IRC logs.
Some domains redirect away from GitLab if you don't provide them with a
path (like /explore
or /help
).