feat: add initial People Playground mod development kit

extracted_wiki_content/internalReference/imanagedbehaviour.txt

@@ -0,0 +1,18 @@
+URL: https://wiki.studiominus.nl/internalReference/IManagedBehaviour.html
+Title: People Playground Modding - IManagedBehaviour
+==================================================
+
+public interface IManagedBehaviour
+Used by the BehaviourManager. Behaviours that implement this interface can be updated by a manager.
+Methods
+void ManagedUpdate()
+Called every update
+
+void ManagedFixedUpdate()
+Called every fixed update
+
+void ManagedLateUpdate()
+Called every late update
+
+bool ShouldUpdate()
+Should this behaviour be updated?