Add modules to modules/index.rst

[crnsh]

Add vector_numpy_integer_dense and vector_numpy_dense so that hyperlinks work again.

📚 Description

This attempts to fix #35444 by adding the correct modules in index.rst. Currently Vector_numpy_dense can be accessed through the index page, but not through the Base class link of Vector_double_dense. Need help resolving this issue.

📝 Checklist

• The title is concise, informative, and self-explanatory.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have updated the documentation accordingly.

@mkoeppe

[crnsh]

Additionally, there are quite a few .pyx files which aren't displayed in the documentation but exist in the codebase. A mini low hanging fruit project might involve identifying all of them and adding them to the documentation. It'll also be insightful to identify why these files aren't included in the documentation. Even though the instructions are in the docs, the reviewer's checklist mentions checking the references docs but these instructions aren't mentioned explicitly, so maybe it got missed?

[github-actions]

Documentation preview for this PR is ready! 🎉
Built with commit: 80a3505

[crnsh]

Weirdly enough it's working on the documentation preview. Why would it work here, but not locally? Did I build the documentation incorrectly? I did the basic ./sage --docbuild reference html command

[mkoeppe]

The reference manual is built as a "multidoc", which requires several passes. make doc-html orchestrates this

[mkoeppe]

A mini low hanging fruit project might involve identifying all of them and adding them to the documentation. It'll also be insightful to identify why these files aren't included in the documentation

Yes, that would be great!