[Feature/Bug]: Fix hint / tooltip visual bug and add icon to label

[lukasoppermann]

Hey, great tool! ❤️

Often configuration settings are rather complex in what they do. To allow users to understand them it would be good if a description or tool tip could be added to show a longer description.

Just to illustrate the icon idea:

[filahf]

I'm after the same thing. I believe https://github.com/pmndrs/leva/blob/main/docs/getting-started/inputs.md#hint is the intended feature for this, but it's currently broken (see #486).

[lukasoppermann]

Ahh, true, it does work, even if broken.

I guess apart from the visual fix it would be nice to have an (i) icon behind the label to make sure people know that there is a hint.