feat: add initial People Playground mod development kit

extracted_wiki_content/internalReference/behaviourmanager_t.txt

@@ -0,0 +1,19 @@
+URL: https://wiki.studiominus.nl/internalReference/BehaviourManager.html
+Title: People Playground Modding - BehaviourManager<T>
+==================================================
+
+public abstract class BehaviourManager
+Inherits MonoBehaviour
+Base class for behaviour managers like LimbBehaviourManager. They replace and speed up Unity's default nightmare message system hell way of updating things. It also provides some certainty when it comes to updating order and allows more update passes.
+Methods
+protected abstract IList<T> GetCollection()
+Should return the collection of behaviours in the world, usually handled by the behaviour itself using a static collection that it adds and removes itself to and from.
+
+protected virtual void Update()
+Run the main update pass. Calls IManagedBehaviour.ManagedUpdate for every existing item in the collection if IManagedBehaviour.ShouldUpdate returns true.
+
+protected virtual void FixedUpdate()
+Run the fixed update pass. Calls IManagedBehaviour.ManagedFixedUpdate for every existing item in the collection if IManagedBehaviour.ShouldUpdate returns true.
+
+protected virtual void LateUpdate()
+Run the late update pass. Calls IManagedBehaviour.ManagedLateUpdate for every existing item in the collection if IManagedBehaviour.ShouldUpdate returns true.