Binary Search Trees 404 Missing

[TheFern2]

I'll leave this one for someone else so they can get a PR : )
Either shortcut needs to be removed from readme.md or Binary_Search_Trees.md needs to be added.
There is already a trees.md so wasn't sure which route you want to take.

[aspittel]

Oh, this used to exist, but I deleted it for some reason... It would be awesome to have someone add their own!