Fix backends toctree

[rascani]

Summary

Update the toctree links to match the backend table links.

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/16844

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

✅ No Failures

As of commit e9abb72 with merge base 849b733 ():
💚 Looks good so far! There are no failures yet. 💚

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[github-actions]

This PR needs a release notes: label

If your change should be included in the release notes (i.e. would users of this library care about this change?), please use a label starting with release notes:. This helps us keep track and include your important work in the next release notes.

To add a label, you can comment to pytorchbot, for example
@pytorchbot label "release notes: none"

For more information, see
https://github.com/pytorch/pytorch/wiki/PyTorch-AutoLabel-Bot#why-categorize-for-release-notes-and-how-does-it-work.

[psiddh]

Accepting it unblock. Once the doc build is done, lets verify all the links

[Copilot]

Pull request overview

Updates backend documentation navigation so the backend overview table and hidden toctree point to the same backend overview pages (using consistent relative paths).

Changes:

• Updated backend overview table links to use consistent relative paths to backend overview pages.
• Updated the hidden toctree in backends-overview.md to reference the same overview documents.
• Removed a redundant hidden toctree from the NXP dim-order page.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
docs/source/backends/nxp/nxp-dim-order.md	Removes an extra hidden toctree from the page footer.
docs/source/backends-overview.md	Aligns backend table links and the hidden toctree to the same backend overview documents using relative paths.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The example command uses --neutron_converter_flavor SDK_25_12, but the surrounding text references MCUXpresso SDK 25.06. Since the docs elsewhere indicate the converter flavor should match the MCUXpresso SDK version, this is confusing—please align the SDK version mentioned in the text and the converter flavor used in the command (pick one version and use it consistently).

[rascani]

Fixed in #16861