Translation to Spanish

Hi there 👋

Let's translate the course to `Spanish` so that the whole community can benefit from this resource 🌎!

Below are the chapters and files that need translating - let us know here if you'd like to translate any and we'll add your name to the list. Once you're finished, open a pull request and tag this issue by including `#issue-number` in the description, where `issue-number` is the number of this issue.

> 🙋 If you'd like others to help you with the translation, you can also post in our [forums](https://discuss.huggingface.co/c/course/20) or tag [@_lewtun](https://twitter.com/_lewtun) on Twitter to gain some visibility.

##Chapters

**Unit 0: Welcome to the course!**

- [x] [introduction.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter0/introduction.mdx)
- [x] [get_ready.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter0/get_ready.mdx)
- [x] [Community.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter0/community.mdx)

**Unit 1: Working with audio data**

- [x] [introduction.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/introduction.mdx)
- [x] [audio_data.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/audio_data.mdx)
- [x] [load_and_explore.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/load_and_explore.mdx)
- [x] [preprocessing.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/preprocessing.mdx)
- [x] [streaming.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/streaming.mdx)
- [x] [quiz.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/quiz.mdx)
- [x] [supplemental_reading.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter1/supplemental_reading.mdx)

**Unit 2: A gentle introduction to audio applications**

- [x] [introductoin.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter2/introduction.mdx)
- [x] [audio_classification_pipeline.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter2/audio_classification_pipeline.mdx)
- [x] [asr_pipeline.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter2/asr_pipeline.mdx)
- [x] [hands_on.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter2/hands_on.mdx)

**Unit 3: Transformer architectures for audio**

- [ ] [introduction.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter3/introduction.mdx)
- [ ] [ctc.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter3/ctc.mdx)
- [ ] [seq2seq.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter3/seq2seq.mdx)
- [ ] [classification.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter3/classification.mdx)
- [ ] [quiz.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter3/quiz.mdx)
- [ ] [supplemental_reading.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter3/supplemental_reading.mdx)

**Unit 4: Build a music genre classifier**

- [ ] [introduction.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter4/introduction.mdx)
- [ ] [classification_models.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter4/classification_models.mdx)
- [ ] [fine_tuning.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter4/fine_tuning.mdx)
- [ ] [demo.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter4/demo.mdx)
- [ ] [hands_on.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter4/hands_on.mdx)

**Unit 5: Automatic Speech Recognition**

- [ ] [introduction.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/introduction.mdx)
- [ ] [asr_models.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/asr_models.mdx)
- [ ] [choosing_dataset.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/choosing_dataset.mdx)
- [ ] [evaluation.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/evaluation.mdx)
- [ ] [demo.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/demo.mdx)
- [ ] [hands_on.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/hands_on.mdx)
- [ ] [supplemental_reading.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/chapter5/supplemental_reading.mdx)

**Course Events**

- [ ] [introduction.mdx](https://github.com/huggingface/audio-transformers-course/blob/main/chapters/en/events/introduction.mdx)

Start with the unchecked English MDX files linked under chapters/en/chapter3, chapter4, chapter5, and events. Translate the selected chapters into Spanish, preserve the course structure and links, then open a pull request and reference issue #66 in its description.

Written by the indexing model from the issue text.