Spanish translation of the file training.mdx
I made the translation of the **training.mdx** file in collaboration to the transformers/doc/ documentation, there I created a new folder called source_es where I hosted my training.mdx document translated to Spanish, contributing to the Spanish-speaking community. 
[forum](https://github.com/huggingface/transformers/issues/15947)

Approved by @omarespejel
Documentation: @sgugger



_The documentation is not available anymore as the PR was closed or merged._<|||||>@sgugger Of course, I will make the changes you indicate, leaving the syntax as per the original documentation. I have a question, I see that most of the conflicts are because of the links, do I leave all the links or remove them? I think these are important.<|||||>As soon as the syntax is reviewed by @yharyarias, I will review the Spanish.<|||||>The links are automatically generated by our doc building tool. You should leave them as they are in the `training.mdx` file English version (for instance [`Trainer`]).<|||||>Perfect! I'll follow your suggestions, thank you @sgugger 🙌🤗<|||||>I just uploaded the changes you suggested @sgugger I'll be watching for your review.<|||||>Thanks! Will review the translation.<|||||>I made the last changes suggested by @omarespejel , I think everything is ok, this is my first contribution and there will be more to come, I have loved collaborating with open source. Thank you very much 🤗 @sgugger @LysandreJik  and @omarespejel <|||||>Thanks, @yharyarias! There are still a couple of comments unresolved. <|||||>IMO it is good to go :+1: Thank you @yharyarias!  <|||||>Thanks again for your PR. Merging this but we will wait a little bit more to serve a doc in Spanish mainly:
- to have a few more pages
- to automatically redirect to English doc when the page is not available in Spanish.

I will put a comment here when the page is live (hopefully in a week or two!)<|||||>@sgugger Thank you, of course I will continue to contribute, I'm currently working on the translation of another document to add to source_es.