Missing sections in Spanish documentation

[donelianc]

Expected output: Nested sections with proper documents in Spanish translation.
Current output: Some sections are missing (but docs are present), so documents are not correctly organized

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After contributing to #15947, I noticed _toctree.yml for the Spanish translation is not following the proper order as the original documentation.

For example, there is no General Usage section in the Spanish version, but the Create a custom architecture (create_a_model) document Is present.

Contributions to #15947 missed adding the right sections updating _toctree.yml.

[donelianc]

Hi @sgugger. Maybe you can help me to verify this issue I just opened. I attached a PR to fix it (you might also be the right person to review and approve it). Thanks!