Update workflow direction to include how to push / pull changes

[pviolette3]

We need to include instructions on how to push / pull from the repo, for the cases when the shiny "merge branch automatically" button doesn't work (this will be a lot of the time).

One thing that might simplify our source code (but be more complicated for users) is rebase. I found how to rebase a PR which goes over how to pull / push. They squash all of the commits they make into a single commit using rebase. They also never use merge, just rebase their single commit on top of latest master.