Substitute relative paths with absolute links.

docs/community/roadmap.md

docs/contact.md

docs/converting-to-bids.md

docs/data.md

docs/data/can-i.md

docs/data/data-management-plans.md

docs/data/docker.md

docs/data/how.md

docs/data/when.md

docs/data/xnat-tools.md

docs/getting-started.md

docs/gitlab.md

docs/gitlab/1-2-tools-markdown.md

docs/gitlab/1-3-tools-atom.md

docs/gitlab/2-3-starting-local-repo.md

docs/gitlab/2-4-starting-git-basics.md

docs/gitlab/3-2-collaborating-fork-their-repo.md

docs/gitlab/3-3-collaborating-play-with-this-page.md

docs/gitlab/4-1-you-make-your-repo.md

docs/gitlab/4-3-you-make-your-pages-site.md