Update readme.

README.md

@@ -17,6 +17,10 @@ This script is based on the netsked concept from Bob Bruninga, WB4APR found here
 - http://www.aprs.org/info/netsked.txt
 - http://www.aprs.org/info/freqspec.txt
 
+This code was almost entirely written by https://github.com/ufergus and sourced from 
+https://github.com/ufergus/arNetSked. Changes by W1CDN are minor to allow for more recent
+Python versions (~3.13).
+
 # Requirements
 - python3-click
 - python3-tz