Rethink async/isgenerator and alike.

[Carreau]

right now, we store a kind to tell us wether something is builtins, generator...

https://github.com/jupyter/papyri/blob/45c158d0e8011fe0bb23e6a5eb4a4b6e4e521245/papyri/signature.py#L90-L99C13

I'm not sure this is the best way as a builtin can be a coroutine function ... etc. It might be a good idea to rethink what we should store and how.

[Carreau]

Expanding a bit on this, to both try to get things out of my head, and take the habit of making longer description.

Some of this information is likely necessary for rendering (like do you show def vs async def), but can be used for other things, like there is a search field, we could have a is:generator filter for example, or warn that there is no Yield section in the docs.

In general we should try to keep information when we can, so that the frontend can decide what an how to render it.

[melissawm]

Do we have any cases of this? I could only find examples of "functions" throughout all the toml examples and the tests.

[Carreau]

In papyri itself, I don't think there are any in the tests. We should add those.