Use `qa/` prefix instead of `stage-`

[amar47shah]

Also:

• Improve clarity of instructions

Reasons for qa/ naming convention:

We currently use branches with slash (/) delimiters. This means that our branches often look like this: f/my-feature.

Given a release branch f/my-feature, it's awkward to apply the stage- prefix: stage-f/my-feature, since this represents a "directory" relationship in the git filesystem, where stage-f is the directory.

Furthermore, staging is the name of our staging app git remote, which means that we cannot use staging/ as a prefix instead of stage-. Using stage/ might also cause confusion.

Therefore, to accommodate the slash delimiters most gracefully, and avoid confusion with the staging/ prefix of branches that live on the staging remote, this change proposes qa/ as the convention:

release branch: f/my-feature qa branch: qa/f/my-feature

[KrishnaKulkarni]

LGTM

[switzersc]

Ditto!

[amar47shah]

Awesome! thanks @switzersc @KrishnaKulkarni.

Merging now.