Create a local guide to the pull request workflow

[phaustin]

Something like: https://github.com/eoas-ubc/eoas_tlef/blob/master/docs/Git_workflow.md -- but with specific cases, dos and don'ts, etc.

Some questions to consider:

1. Why we don't recommend that you use the default git pull
2. If we don't recommend you use it, why is it the default?
3. What should you do instead?
4. What problems does that avoid?

[fhmjones]

Phil's initial copy of the Chase Pettit outline is very clear.

We perhaps don't need the instructions for managing pull requests from the original repo owner's perspective, so I removed that and left a pointer in case there is interest. The intro was adjusted slightly too.

Answering the 4 questions is a good idea. Perhaps when I am more familiar because the learning curve seems steep.

[fhmjones]

This card should be in the "in progress" column because the first draft is here https://fhmjones.github.io/git-workflows.html. Currently this is a first attempt at the "how to".
Still needed: short answers to original questions 1, 2, and 4. Although - in documentation like this, the "why" should be kept short, and perhaps flagged as "peripheral" to the workflow or preferred (or recommended) workflow.