UI Hints for Model Behaviours

[humphd]

Spin-off from https://github.com/tarasglek/chatcraft.org/pull/664#issuecomment-2242881213

Not all models support the same features. For example, some can handle images or audio, some can do function calling, etc. However, you have to know about this to use it.

We should come up with a way to hint to users what a model can do. Maybe in the list of models we add icons? Maybe once you've selected a model, we update the prompt area with some icons to indicate what can or can't be done?

Needs thought.