added help to query

osxphotos/cmd_line.py

@@ -123,6 +123,9 @@ def dump(cli_obj):
 @click.pass_context
 def query(ctx, cli_obj, keyword, person, album, uuid, json):
     """ query the Photos database using 1 or more search options """
+    if not keyword and not person and not album and not uuid:
+        print(cli.commands['query'].get_help(ctx))
+    else:
         photos = cli_obj.photosdb.photos(
             keywords=keyword, persons=person, albums=album, uuid=uuid
         )