feat: add initial People Playground mod development kit

extracted_wiki_content/internalReference/physicalbehaviour_penetration.txt

@@ -0,0 +1,42 @@
+URL: https://wiki.studiominus.nl/internalReference/PhysicalBehaviour_Penetration.html
+Title: People Playground Modding - PhysicalBehaviour.Penetration
+==================================================
+
+public class Penetration
+This nested type resides in PhysicalBehaviour
+[System.Serializable]
+Represents an object stabbing another object.
+Fields
+public PhysicalBehaviour Stabber
+The object that did the stabbing.
+
+public PhysicalBehaviour Victim
+The object that has been stabbed.
+
+public SliderJoint2D Joint
+The associated slider joint.
+
+public float Duration
+The amount of time this penetration has existed. Used to prevent the stabber from falling out immediately after it has lodged itself in.
+
+public SharpAxis Axis
+The associated SharpAxis on the stabber.
+
+public List<Collider2D> RelevantColliders
+The colliders that the stabber ignores collision with.
+
+public Vector2 CurrentConnectedAnchor
+The local anchor on the victim
+
+public bool Active
+Is this penetration still ongoing?
+
+Methods
+public Vector2 GetDirection()
+Get the current (!!) world space normalised direction of the penetration
+
+public Vector2 GetPoint()
+Get the current (!!) world space point of the penetration
+
+public float GetCurrentDepth()
+Returns the depth of the stabber in the victim.