Solve link error in internal_mechanism documentation (#3506)

[alvaro-mazcu]

What does this PR do?

This PR changes a documentation link that was not correct. Now, you should be able to access docs/source/package_reference/torch_wrappers.md from docs/source/concept_guides/internal_mechanism.md, solving the link error in this page.

Now, at least in GitHub, the link works.

Fixes #3506

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,
  Pull Request section?
• Was this discussed/approved via a Github issue or the forum? Please add a link
  to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

@SunMarc, as he commented on the issue.

How to test?

1. Go to the file that contained the error in my fork and my branch: https://github.com/alvaro-mazcu/accelerate/blob/patch-1/docs/source/concept_guides/internal_mechanism.md
2. Click on the last link. You should get redirected to docs/source/package_reference/torch_wrappers.md smoothly.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[SunMarc]

Thanks !

[alvaro-mazcu]

Hey @SunMarc! Do you know why the quality check is failing? I see that it also fails in other PRs

[SunMarc]

please update your PR to the latest commit, I fixed the issue!

[alvaro-mazcu]

please update your PR to the latest commit, I fixed the issue!

Done @SunMarc ! Thanks for fixing the error. PR is ready to be approved again and merged.