Update firestore.yml

Author: ncooke3

.github/workflows/firestore.yml

@@ -40,7 +40,7 @@ jobs:
             sources:
               # Firestore sources
               - 'Firestore/**'
-              - '!**/*.md'
+              - '!Firestore/**/*.md'
       - uses: dorny/[email protected]
         id: related_changes
         with: