[ create_a_model.mdx ] translate to pt
# What does this PR do?

Creates a new file called create_a_model.mdx in docs/source/pt
Translates all the content of the base create_a_model to pt-br

Fixes issue #16824

## Before submitting
- [X] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [X] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
- [X] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [X] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [X] Did you write any new necessary tests?
_The documentation is not available anymore as the PR was closed or merged._<|||||>Obrigado @Fellip15! Thank you for your translation, and sorry for my late review. 

The text looks good to me, but the tests seem to have a weird loop. I can not find the reason, WDYT @sgugger?