Added decoding to detect an external antenna (extension) and its status.

[PierreDeQuebec]

I propose to add PGPTOP decoding to get the status of an external antenna if there is one. How can I submit the code?

[dhalbert]

You can make a pull request. We have a tutorial here: https://learn.adafruit.com/contribute-to-circuitpython-with-git-and-github

[PierreDeQuebec]

Thank you for the link. I followed the instructions and made a "pull request". I had to make a correction in my "pull request" to correct a faulty copy-paste in the submitted code. We'll put that down to rookie mistakes.