Update gamemodes.py.example

Old file was out-of-date wrt recent changes. Add in missing imports and fix the do not edit warning to be less wonky. Also add in skeleton example gamemode

gamemodes.py.example

@@ -1,17 +1,26 @@
 # To add new game modes, rename this file to 'gamemodes.py' then add them in
-# Basic frame for the game modes in src/gamemodes.py
 
-# *** DO NOT TOUCH ANY OF THE CODE BETWEEN THE LINES 4 AND 17 ***
-
-from src.messages import messages
+from src.gamemodes import (GameMode, game_mode, reset_roles)
 import src.settings as var
+from src.utilities import *
+from src.messages import messages
+from src import events
 
-from src.gamemodes import (
+####################################################################
+# DO NOT EDIT ANYTHING ABOVE THIS LINE, ADD CUSTOM GAMEMODES BELOW #
+####################################################################
 
-    GameMode,
-    game_mode,
-    reset_roles,
+@game_mode("mymode", minp=4, maxp=24, likelihood=5)
+class MyMode(GameMode):
+    """Example mode. This doesn't do anything special yet."""
+    def __init__(self, arg=""):
+        super().__init__(arg)
+        # Put gamemode settings here
 
-)
+    def startup(self):
+        # Register events here
+        pass
 
-# Add custom game modes from this point
+    def teardown(self):
+        # Unregister events here
+        pass