put_flash lack documentation, :warning not supported

[ponychicken]

In the put_flash docs, there is no clear mention what types are supported. Seems like :info, :error, but not :warning.

It would be good to state this and maybe also support a ;warning flash

[SteffenDE]

This is because put_flash does not care about the types at all. The info and error flash come from the generated core components: https://github.com/phoenixframework/phoenix/blob/25e891f172045aa0391d30bfd794111235041159/installer/templates/phx_web/components/core_components.ex#L147-L151

So if you add a warning flash there and also implement the styles in your flash component, it will work just like the others. You could also call it warn, information or whatever key you like :)

A PR to improve the docs is always appreciated though!

[ponychicken]

Ok, I will add something along this lines to the docs.