wip: add coveralls support for displaying coverage

Author: chadsec1

README.md

@@ -1,5 +1,6 @@
 ## Coldwire - An ultra secure messenger for the ultra paranoid
 ![Tests](https://github.com/Freedom-Club-FC/Coldwire/actions/workflows/tests.yml/badge.svg)
+![Coverage](https://coveralls.io/repos/github/Freedom-Club-FC/Coldwire/badge.svg?branch=main)
 
 A post-quantum secure messenger for the ultra paranoid