Update completion.py: check also for branch main

Author: m-aciek

completion.py

@@ -22,7 +22,7 @@ def branches_from_devguide(devguide_dir: Path) -> list[str]:
 
 def get_completion(clones_dir: str, repo: str) -> tuple[float, 'TranslatorsData', str]:
     clone_path = Path(clones_dir, repo)
-    for branch in branches_from_devguide(Path(clones_dir, 'devguide')) + ['master']:
+    for branch in branches_from_devguide(Path(clones_dir, 'devguide')) + ['master', 'main']:
         try:
             git.Repo.clone_from(
                 f'https://github.com/{repo}.git', clone_path, branch=branch