RFC Submission: Postman to Bruno

[rstens]

Issue #: 22574

Description of changes:
An RFC proposing a change for Postman to Bruno for API testing.
Re-submission as I picked up spurious other commits.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the namex license (Apache 2.0).

[rstens]

Previous comment from @doug-lovett :

I found the transition from Postman to Bruno painless, the experience is similar to Postman. My evaluation included:

• creating a collection from scratch based on a Postman one
• setting up and using environment variables
• using request variables
• using test assertions
• requesting a report and saving to file.
  Loading a request payload from file, free with Postman, comes with the Bruno Gold license ($20), along with some other features.