[V3] Optimize the backup command (#1666)

* [V3 Core] Enhance [p]backup to exclude some files

* Backup the repo list too

* Lol Sinbad's pre-commit hook

* Add option of sending the backup to the owner via DM

* Drop an unnecessary config object in RepoManager

* Move the backup functionality in redbot-setup to the new stuff

* More work on implementation, including backing up the instance data

redbot/cogs/downloader/repo_manager.py

@@ -496,8 +496,7 @@ class Repo(RepoJSONMixin):
 
 class RepoManager:
 
-    def __init__(self, downloader_config: Config):
-        self.downloader_config = downloader_config
+    def __init__(self):
 
         self._repos = {}