Added Python solution for 94.Binary Tree InOrder Traversal (#129)

Author: JoyKrishan

Algorithms/Easy/94_BinaryTreeInorderTraversal/Solution.py

@@ -0,0 +1,20 @@
+class Solution:
+    def inorderTraversal(self, root: Optional[TreeNode]) -> List[int]:
+        stack = []
+        output_array = []
+
+        if root is None:
+            return output_array
+
+        current = root
+
+        while current is not None or stack:
+            while current is not None:
+                stack.append(current)
+                current = current.left
+
+            current = stack.pop()
+            output_array.append(current.val)
+            current = current.right
+        
+        return output_array