include readmes in version bump

Author: diegomarquezp

release-please-config.json

@@ -10,7 +10,11 @@
       "bump-minor-pre-major": false,
       "bump-patch-for-minor-pre-major": false,
       "draft": false,
-      "prerelease": false
+      "prerelease": false,
+      "extra-files": [
+        "README.md",
+        "bom/README.md"
+      ]
     }
   },
   "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"