Add message in linter

Author: vkucera

Scripts/o2_linter.py

@@ -1688,6 +1688,7 @@ def main():
     n_files_bad = dict.fromkeys(test_names, 0)  # counter of files with issues
 
     # Report overview before running.
+    print("This linter belongs in the base branch.")
     print(f"Testing {len(args.paths)} files.")
     # print(args.paths)
     print("Enabled tests:", test_names)