docs(website): add custom edge props closes #608

website/src/markdown/docs/api/edge-types.md

@@ -26,3 +26,29 @@ edgeTypes={{
 Now you could use the new type `special` for an edge.
 The `straight`, `default` and `step` types would still be available unless you overwrote one of them.
 There is an implementation of a custom edge in the [edges example](/examples/edges/).
+
+
+## Custom Edge Props
+
+Custom edges are wrapped. They receive the following props:
+
+- `source`: string (node id)
+- `target`: string (node id)
+- `selected`: boolean
+- `animated`: boolean
+- `label`: string
+- `labelStyle`: svg attributes
+- `labelShowBg`: boolean
+- `labelBgStyle`: svg attributes
+- `labelBgPadding`: number
+- `labelBgBorderRadius`: number
+- `data`: object
+- `style`: svg attributes
+- `arrowHeadType`: 'arrow' | 'arrowclosed'
+- `sourceX`: number
+- `sourceY`: number
+- `targetX`: number
+- `targetY`: number
+- `sourcePosition`: 'left' | 'top' | 'right' | 'bottom'
+- `targetPosition`: 'left' | 'top' | 'right' | 'bottom'
+- `markerEndId`: string