chore/update-readme-staging-usage

[hugomontero]

Description

This PR will add a section to explain how to use staging versions for testing purposes

How to Test

1. Attempt to use the instructions described in the changes.

Related Issues / Discussions

Completeness

• [x] User is totes amazing for contributing!
• [x] Contributor has signed CLA
• [x] Problem and solution clearly stated
• [x] Tests have been provided
• [x] Docs have been updated
• [x] CI is passing

[keeramis]

I will test this today - thanks for putting this together @hugomontero