Binary Search Tree (BST) - Wrong `count` explanation

[marcopaivaf]

Hey!

Thank you so much for putting all this together. Really great stuff!
I just notice a small, minor typo in the BST readme that may confuse people.

In the Binary Search Tree (BST) readme, it describes the count variable as follow:

The count property determines how many nodes are in the subtree described by this node. This does not just count the node's immediate children but also their children and their children's children, and so on. If this particular object is the root node, then it counts how many nodes are in the entire tree. Initially, count = 0.

It says that initially, count = 0. Although, this is not true as the node always counts itself (+1):
(left?.count ?? 0) + 1 + (right?.count ?? 0)