Restore banner image in README

Author: VARUN3WARE

README.md

@@ -1,5 +1,7 @@
 # pytorch-dml
 
+![pytorch-dml Banner](banner.png)
+
 [![PyPI version](https://badge.fury.io/py/pytorch-dml.svg)](https://badge.fury.io/py/pytorch-dml)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![Tests](https://img.shields.io/badge/tests-passing-brightgreen)](tests/)