fix changelog

Author: RonnyPfannschmidt

CHANGELOG.rst

@@ -3,9 +3,9 @@ v3.0.0
 
 * introduce pre-commit and use black
 * print the origin module to help testing
-* switch to src layout
+* switch to src layout (breaking change)
 * no longer alias tag and parsed_version in order to support understanding a version parse failure
-* require parse results to be ScmVersion or None
+* require parse results to be ScmVersion or None (breaking change)
 
 v2.1.0
 ======