rssVideos: Add list command

Then you know which video you should watch next :)

config/scripts/rssVideos

@@ -41,6 +41,9 @@ def configure_logging(args: configargparse.Namespace) -> None:
             logger=log,
         )
 
+class RVCommand(enum.Enum):
+    download = "download"
+    list = "list"
 
 class RVElement:
     title: str
@@ -302,6 +305,15 @@ def get_args() -> configargparse.Namespace:
         action="store_true",
     )
 
+    parser.set_defaults(subcommand=RVCommand.download)
+    subparsers = parser.add_subparsers(title="subcommand")
+
+    sc_download = subparsers.add_parser("download")
+    sc_download.set_defaults(subcommand=RVCommand.download)
+
+    sc_list = subparsers.add_parser("list")
+    sc_list.set_defaults(subcommand=RVCommand.list)
+
     args = parser.parse_args()
     args.videos = os.path.realpath(os.path.expanduser(args.videos))
 
@@ -315,14 +327,22 @@ def main() -> None:
     os.makedirs(args.videos, exist_ok=True)
     os.chdir(args.videos)
 
-    database = RVDatabase(args)
-    database.read_feed()
-    cache = RVDatabase.load()
-    if cache:
-        database.read_cache(cache)
-    database.clean()
-    database.act_all()
-    database.save()
+    if args.subcommand == RVCommand.download:
+        database = RVDatabase(args)
+        database.read_feed()
+        cache = RVDatabase.load()
+        if cache:
+            database.read_cache(cache)
+        database.clean()
+        database.act_all()
+        database.save()
+
+    elif args.subcommand == RVCommand.list:
+        cache = RVDatabase.load()
+        if not cache:
+            raise FileNotFoundError("This command doesn't work without a cache yet.")
+        for element in cache.elements:
+            print(element)
 
 
 if __name__ == "__main__":