feat: add initial People Playground mod development kit

extracted_wiki_content/internalReference/mapregistry.txt

@@ -0,0 +1,27 @@
+URL: https://wiki.studiominus.nl/internalReference/MapRegistry.html
+Title: People Playground Modding - MapRegistry
+==================================================
+
+public static class MapRegistry
+The global map registry.
+Methods
+public static void Register(Map map)
+Register a map. Throws an exception if a map with the same identity is already registered.
+
+public static Map GetMap(string identity)
+Returns the map with the given identity or null if nothing was found.
+
+public static bool HasMap(string identity)
+Returns true if the map with the given identity is registered, false otherwise.
+
+public static bool TryGetMap(string identity, out Map map)
+Returns true if the map exists, false otherwise. Assigns the resulting map to the outgoing argument, which will be null if nothing was found.
+
+public static void Clear()
+Clear the registry. Does not destroy anything, only clears the registry.
+
+public static IEnumerable<Map> GetAllMaps()
+Enumerate through all non-null maps
+
+public static void Deregister(Map map)
+No description provided