feat: add initial People Playground mod development kit

extracted_wiki_content/internalReference/stabbing.txt

@@ -0,0 +1,22 @@
+URL: https://wiki.studiominus.nl/internalReference/Stabbing.html
+Title: People Playground Modding - Stabbing
+==================================================
+
+public struct Stabbing
+Structure that describes a stab event
+Fields
+public PhysicalBehaviour stabber
+The sharp object that does the stabbing
+
+public PhysicalBehaviour victim
+The soft object that has been stabbed
+
+public Vector2 normal
+The normal vector of the impact in world space at the time of stabbing
+
+public Vector2 point
+The point of impact in world space at the time of stabbing
+
+Methods
+public (constructor) Stabbing(PhysicalBehaviour stabber, PhysicalBehaviour victim, Vector2 normal, Vector2 point)
+No description provided