weewx-stackedwindrose updated for weewx 5.5

[Vince Skahan]

Updated Gary's old 2023 extension to catch up to the new stop_event change in weewx 5.5 and added minor readme updates due to python 3.12 'again' breaking things.  Sigh.  Python.

Tested in a pip install of weewx 5.5 using python 3.13.5

https://github.com/weewx-contrib/stackedwindrose-extension

Changes:

  * added the new stop_event=None item to __init__

  * some readme additions to hopefully help

Short description - no change in functionality. Just made the required change to have __init__ not blow up if you're running weewx 5.5.  It simply ignores any stop_event that is passed in, so it should work as it always has.

Users of weewx 'prior' to 5.5 should continue to use the old 2023 version 3.0.2 that is tagged in the repo.

Thanks to PaulA for help on testing etc. on this one....