Minor refactor for hyperelliptic curve

[user202729]

As in the title. See the code for detail.

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies

[github-actions]

Documentation preview for this PR (built with commit ea74b42; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

[orlitzky]

Can you mention the defaults if replacement and replacement_rst_doc are left unspecified (=None)?

The generated HTML looks a little bit weird because sphinx puts parentheses after the method name when you use :meth:foo. It might look better if you wrote (for example) :meth:foo with algorithm="pari" instead, but this is just an idea. If you are happy with it, whatever, it's temporary.

Otherwise LGTM

[user202729]

how about :meth:`frobenius_polynomial(algorithm="pari") <frobenius_polynomial>`​ (which will render as frobenius_polynomial(algorithm="pari") in a consecutive code block, but clicks through to frobenius_polynomial)?

[orlitzky]

how about :meth:`frobenius_polynomial(algorithm="pari") <frobenius_polynomial>`​ (which will render as frobenius_polynomial(algorithm="pari") in a consecutive code block, but clicks through to frobenius_polynomial)?

That sounds even better, I didn't know that was an option.

[orlitzky]

The new docs look great. Please still mention the defaults when replacement and replacement_rst_doc are left unspecified, but you can positive-review it after that.

[user202729]

I guess https://github.com/sagemath/sage/pull/39161/files#diff-7647f4a9c65536028428ee1620ece71255c8c4ddc78ecb3db5540de2bb89d047R159 has something similar. (or maybe faster.)

haven't checked carefully.