doc: replace the compatibility badge with pypi package badge in the readme (#6000)
doc: replace the compatibility badge with pypi package badge in the readme (#6000)

The links to the compatibility badge and page do not exist any more (added at https://github.com/tensorflow/tensorboard/pull/2328).
tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard