Remove installers

[k1o0]

Is your feature request related to a problem? Please describe.
Installers take up a lot of space and should not be in the main repo. If they're removed Git will try to redownload them which is a pain. Also these installs have no business being in the docs folder.

Describe the solution you'd like
Move these installers to a new dedicated repo called Rigbox-installers. Change the scripts to use git.runCmd to clone this repo, call the installers, then optionally delete the repo.

Describe alternatives you've considered
Git recommends a large file system option but that requires a separate download of their software, which makes the process more work than it more complicated.

Additional context
Jai added these things to master. The main install guide doesn't mention this script so it doesn't require a lot of work to remove installers from the repo.