Adding ASR pipeline example.
Author: Narsil
Pull request: yes

# What does this PR do?

This is the first PR of a series that will aim to add examples for ALL pipelines.

The example uses `pipeline` instead of the documented `AutomaticSpeechRecognitionPipeline` intentionally.
It break my personal idea of documenting really what we're documenting, but it makes the example a lot more simple and enables to link to the pipeline tutorial for the "orthogonal" arguments (notably `batch_size`.)

https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226/en/main_classes/pipelines#transformers.AutomaticSpeechRecognitionPipeline.example

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Comments:
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226). All of your documentation changes will be reflected on that endpoint.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226). All of your documentation changes will be reflected on that endpoint.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226). All of your documentation changes will be reflected on that endpoint.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226). All of your documentation changes will be reflected on that endpoint.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226). All of your documentation changes will be reflected on that endpoint.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20226). All of your documentation changes will be reflected on that endpoint.