Fix binary tree code

[9inpachi]

Fixed the traverse function which was affecting findParentOfToBeDeletedNode function by returning the root as parent every time.

Also fixed the deleteNode function which was not working for the deletion of root node and some other cases.

I have simpler version for the deleteNode function if you want to use that in the guide - let me know - I will add replace it in this PR.

const deleteNode = (root: MyNode, value: number): MyNode => {
  if (value < root.value) {
    root.left = deleteNode(root.left, value);
  } else if (value > root.value) {
    root.right = deleteNode(root.right, value);
  } else {
    if (root.left && !root.right) {
      root = root.left;
    } else if (root.right && !root.left) {
      root = root.right;
    } else if (root.left && root.right) {
      const node = mostLeftNode(root.right);
      const temp = node.value;
      root.value = temp;
      root.right = deleteNode(root.right, temp);
    } else {
      root = undefined;
    }
  }
  return root;
}

Thanks.

[AvraamMavridis]

thx @9inpachi