Add model card creation snippet to example scripts
# What does this PR do?

This PR adds model card creation in case the `push_to_hub` argument is not used.

@patrickvonplaten 
Looks good to me - thanks for the PR!<|||||>@sgugger Does this look fine? I went over the scripts in `pytorch` examples.<|||||>That's great! Can you just run `make style` on your branch to take care of the quality issue?