Translate installation.mdx to Spanish
# What does this PR do?

Adds the translation of [installation.mdx](https://github.com/huggingface/transformers/blob/master/docs/source/installation.mdx) to Spanish.

Fixes # [15947](https://github.com/huggingface/transformers/issues/15947) (issue)

## Before submitting
- [✓] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [✓] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/master/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?

_The documentation is not available anymore as the PR was closed or merged._<|||||>Thanks @lilianabs! 🤗<|||||>@omarespejel all of the changes have been added, thank you! :) <|||||>Thank you @lilianabs! 🤗.  @sgugger LGTM 👍  