In the screenshot in the repo, there's a node with the text "a mind mapping tool". It has 5 children, but the first child "text-based (terminal application)" is above it. So the more children a node has, the further above it the first child is. What if it was aligned so that the first child is at the same height as its parent? Then it might look more natural like a list, and read easier since the children start at the same height as the parent rather than at some arbitrary point above it.

This would help with flow, because then you can read left to right and scan downwards. Right now you have to keep jumping up to find the first child and then scan down to read all the children.