torch.distribution examples rendering issue (#81611)
# Issue
"Example" section in the documentation is not rendering correctly for [`torch.distributions.transforms.CatTransform`](https://pytorch.org/docs/stable/distributions.html#torch.distributions.transforms.CatTransform)
and
[`torch.distributions.transforms.StackTransform`](https://pytorch.org/docs/stable/distributions.html#torch.distributions.transforms.StackTransform)
# Fix
Simply add an empty line after the `Example::` keyword to fix the issue.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81611
Approved by: https://github.com/kit1980
