title: Moving an existing GitLab project into a new subgroup
body: <p>Just started out using self hosted GitLab... it looks like it's going to be really useful moving towards a DevOps workflow.</p>
  
  <p>Anyway, after migrating about 20 local Git repositories to the new GitLab server, neatly arranged into 4 groups. I then noticed you can actually have sub-groups within the groups. This would help organisation even further, but I'm struggling to work out how to move the existing projects I've spent a day importing and configuring into a newly created sub-group. Sure I could just create a new project and copy the files over and commit them into the new project, and spend the time reconfiguring the project.</p>
  
  <p>Is there an easy way of moving the existing configured Project from the group into the new subgroup?</p>