Template game = own mod + reusable town_pack

The novel template becomes the intended layering: collection novel_template
lists my_novel_game (its own scenes, scenarios, text), town_pack (reusable
backgrounds and the bar ambience) and the engine. The town entrance and the
home vestibule move from cthangover_game into town_pack instead of being
copied; cthangover_game depends on it. Docs explain how to start a game from
these three layers.

manifest.json

@@ -5,5 +5,5 @@
   "author": "ct",
   "description": "Story content of the Cthangover game: scenes, scenarios, characters, items, quests, backgrounds and the main game collection.",
   "category": "story",
-  "depends": ["shell2d_base>=1", "dialog_base>=1", "interactive_base>=1", "skills_base>=1", "map_base>=1", "ui_base>=1", "characters_base>=1", "items_base>=1", "quests_base>=1"]
+  "depends": ["shell2d_base>=1", "dialog_base>=1", "interactive_base>=1", "skills_base>=1", "map_base>=1", "ui_base>=1", "characters_base>=1", "items_base>=1", "quests_base>=1", "town_pack>=1"]
 }