Docs: 'Git Workflow' README section improvements

[qredwoods]

Context

why does this issue exist? if we're solving a problem, describe the frustrating/problematic experience. If we want something new, describe the general motivation for the feature

Enhance how branching is addressed in the Git Workflow

Branching - Right now we rely on spoken explanation or individuals looking at past branches to guess what the branching convention is.

The current practice is category of branch, ie feature , bugfix, or chore, followed by issue number, followed by issue name.

So if a developer wants to work on issue 9999 which is a bugfix, titled "Use this issue as an example" the branch should be named:
bugfix/9999/use-this-issue-as-an-example

Specifying the convention in the readme would reduce guesswork and promote consistency.

Branch deletion: a branch deletes on merge of the respective PR. In the absence of a merge, if you own a branch and over time it becomes clear you've abandoned it/ don't plant to return to it, please delete it.

Definition of Done

what tangible outcomes define this as issue as complete

Add to the Git Workflow readme section such that it incorporates the above points.

Engineering Details

what sort of details are needed for someone to pickup this issue? Are there any specific files or areas of the code that they should reference?
README.md
The Git Workflow section starts around line 498 of README.md