Change GitLab Runner repository to a new path

We've moved the GitLab Runner project to a new path as described in gitlab-org/gitlab-runner#1195 (closed).

This MR updates all references to gitlab.com/gitlab-org/gitlab-ci-multi-runner and changes them into gitlab.com/gitlab-org/gitlab-runner.

mentioned in issue gitlab-org/gitlab-runner#1195 (closed)

Does this also fix the issue with the edit this page links going to the wrong repo?

@bbodenmiller https://docs.gitlab.com is autogenerated from this repository using nanoc. After a double check I found that there is also an old path in lib/helpers/edit_on_gitlab.rb which is responsible for generating the link that you've mentioned. I've added 35769baa to update also this file.

At this moment I think that all gitlab-ci-multi-runner references should be changed into gitlab-runner.

merged