Updated CHANGES.md

Mentioned code coverage output.

Author: ckadluba

CHANGES.md

@@ -2,6 +2,7 @@
 * Implemented #454: LoggingLevelSwitch support to allows log level manipulation at runtime.
 * Fixed issue #458: Error if enrich nullable int columns by null value
 * Added CodeQL code scanning
+* Generate code coverage file when running tests in Build.ps1
 
 # 6.1.0
 * Fixed issues #207, #435, #419 & #292: Resolve hierarchical property expressions for additional columns