Add RapidAPI

[relyonheaven]

NOTE: Each discrete (stand-alone) request should be in its own issue.

Put "Add ____" as Title

• Done

Provide a link to the proposed addition.
Place link here

Explain why it should be added
RapidAPI for Mac is a free full-featured HTTP client that lets you test and describe the APIs you build or consume.

Additional context
It has a beautiful native macOS interface to compose requests, inspect server responses, generate client code and export API definitions.

Issue Checklist

Put an x in the boxes once you've completed each step. You can also fill these out after creating the issue. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before responding to the issue.

• I have checked for other similar issues
• I have explained why this change is important
• I have added necessary documentation (if appropriate)