Merge pull request #52129 from AnilBK/skeleton2d-ik-doc

Document how to use IK in skeleton2D.

doc/classes/Skeleton2D.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		Skeleton2D parents a hierarchy of [Bone2D] objects. It is a requirement of [Bone2D]. Skeleton2D holds a reference to the rest pose of its children and acts as a single point of access to its bones.
+		To setup different types of inverse kinematics for the given Skeleton2D, a [SkeletonModificationStack2D] should be created. They can be applied by creating the desired number of modifications, which can be done by increasing [member SkeletonModificationStack2D.modification_count].
 	</description>
 	<tutorials>
 		<link title="2D skeletons">https://docs.godotengine.org/en/latest/tutorials/animation/2d_skeletons.html</link>