User stories for git-hack

@charlierudolph @allewun adding user stories that describe end-user value
We don't have it in most other places. If you are fine with adding it everywhere, I can do that. It would look like this:

> As a developer creating a new feature branch while there are conflicting updates on the local and remote main branch
> I want to be given the choices to resolve these differences now or abort
> So that I can finish the operation as planned or postpone it to a better time, and remain productive.

What do you think?