Explain how to override default entry point

[benji-sb]

This PR adds a page in the "Advanced Topics" section of the doc. This new page explains how to override the default entry point in C and have dune compile everything.

For more context on why this could be useful, you can check the Wildcard expansion on Windows topic on the Ocaml Discourse.

[maiste]

Thanks for the contribution! 👍
We are trying to rely more and more on the Diátaxis framework to improve the Dune documentation. In this situation, I would move this to the How-to guide section in the Dune documentation.

@Leonidas-from-XIV, what is your two cents on this?

[Leonidas-from-XIV]

I agree with @maiste, it's definitely more a howto, as it doesn't cover any particular advanced topic about Dune, more about how C stubs work but this has more to do with OCaml than Dune.

Still, we can definitely include it in the documentation.

[benji-sb]

I agree with @maiste, it's definitely more a howto, as it doesn't cover any particular advanced topic about Dune, more about how C stubs work but this has more to do with OCaml than Dune.

Still, we can definitely include it in the documentation.

Moved to the howto section, thanks for the suggestion!

[Leonidas-from-XIV]

I think it could have a bit of a "this is how the result works" section, otherwise it looks good from my point of view.

@christinerose could you please take a look at the text if it is ok that way?

[maiste]

Thanks, the update looks good! I have just one comment and, otherwise, as @Leonidas-from-XIV said, I let @christinerose do her magic (thanks in advance for having a look at this 🙏 )

Also, you need to update your commit to comply with the DCO (see the information).

[Alizter]

Just a quick comment: OCaml doesn't have a notion of "entry point" since basically everything is run in order. Therefore calling it the "C Entrypoint" might be better. This might be clearer to new users who might think that OCaml has entry points.

[benji-sb]

Just a quick comment: OCaml doesn't have a notion of "entry point" since basically everything is run in order. Therefore calling it the "C Entrypoint" might be better. This might be clearer to new users who might think that OCaml has entry points.

I edited the document accordingly, thanks a lot for bringing up this point!

[maiste]

LGTM 👍

[maiste]

The error in the CI is completely unrelated with the PR (as it just modifies the documentation). I think we can merge it.