Adding, deleting, and editing intermediate points of a link

The LinkIntermediatePointsAdorner is responsible for editing actions on a link. This LinkAdorner shows a small blue diamond handle on every intermediate point and allows you to create, edit, or remove intermediate points to any styled link with the value set to Free.
The LinkIntermediatePointsHandle is represented as a small blue diamond drawn on every intermediate link point. These handles are highlighted when you hover over them, and can be dragged to change the intermediate point position. If you click this handle while holding the Shift key, the intermediate point is deleted.
You can add intermediate points to styled links with the value set to Free by Shift-clicking the links where a point needs to be added.