Version control: Add/link to getting started in Oscar

[mirestrepo]

It would be nice to have a Getting Started with git in Oscar section added to the version control page

In my mind there are few things to set up:

1. Set up GitHub credentials. This can be done in three ways
   1a. Use GitHub CLI @hollandjg I feel like you have steps already for this from Brainstorm's workshop
   1b. Forward agent keys. Brad wrote a section in the docs about it, so we can just link to that
   1c. Normal key set up

2. Set up git info. I think this is already in the docs

Anything else?