Mycontrib Added Example for is_tensor API (#55052)
Summary:
[Added Example for is_tensor API](https://github.com/harishsdev/practice/blob/master/changes_to_opensource/is_tensor_example_added.jpg)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55052
Reviewed By: ezyang
Differential Revision: D27523833
Pulled By: gchanan
fbshipit-source-id: 06036342223454856d4cfec46b40a72b311d261f
