copilot: Document changes in CHANGELOG. Refs #589.

Author: RyanGlScott

copilot/CHANGELOG

@@ -1,6 +1,7 @@
-2025-01-31
+2025-02-24
         * Include missing dependencies in installation instructions. (#591)
         * Update version of GHC in README. (#590)
+        * Add example of how to use proveWithCounterExample. (#589)
 
 2025-01-07
         * Version bump (4.2). (#577)