Show HN: Calltree – Neovim's missing call hierarchy UI

Calltree implements the missing "call-hierarchy" tree UI seen in other popular IDE's such as Pycharm and VSCode.

Calltree allows you to start at a root symbol and discover the callers or callees of it.

Subsequently, you can drill down the tree futher to discover the "callers-of-caller" or the "callees-of-callee".

This relationship forms a tree and this is exactly how Calltree works, keeping an in memory representation of the call tree and writing the tree out to an outline form when requested.