Create instructional video for Install GitLab via Omnibus

Need a more up to date video of this. Perhaps include upgrading and uninstalling.

This is for #1593 (closed). Once the video is completed, please upload the video to the Onboarding Folder' in Google drive. If you recorded the video using Zoom, please upload the video+audio version of it so it contains everything.

If your video needs editing, please ping myself (@jcolyer) in this issue and I would be more than willing to do this for you!

~"Team Training"