Feature request: Allow anchors to be placed absolutely or a percentage of total width/height

[samesfahani-tuplehealth]

At the moment, anchors are placed in the middle of the elements (I imagine there is a lot of division by 2 in the code). The feature I am requesting is something like:

<AnchorElement
  id="el1"
  relations={[{ targetId: "el2", sourceAnchor: 'right', targetAnchor: 'left', "sourceAnchorPosition": "10%", "targetAnchorPosition": 10 }]}
>

Where the source anchor starts from 10% of total height and ends 10px down from el2's height.

[pierpo]

Hey, that's a brilliant suggestion 😊
The API looks fine to me.
It sounds feasible, and should not be too hard indeed.

PR welcome if you need this quickly!