Request feature: Add bucle line support

[webserveis]

This library is interesting to create flow diagrams:
It is possible to add that a node can link to another node in order to create a loop?
And customize every node with change background shape?
Connect lines with arrow?

[DennisBlock]

Unfortunately the current algorithm that we use only works with directed rooted trees, which is an acyclic connected graph. In other words, it doesn't work with loops. Therefore we need a different algorithm for this use case. In the future we want to support all different kinds of graphs, so it's definitely coming someday. (Maybe we should then rename this library to GraphView?)

For your other questions: Different background shapes and lines with arrows should be easy to implement, but as I said, without a suitable algorithm you're not gonna get this kind of diagram.