bevy_hints

Hints to future editors that this entity / struct field should be interacted in some way. Sometimes I want to customize how bevy_editor_pls generates UIs for my reflected values or entities. But I want my changes to also reflect in future editors without resorting to one-off patches for certain behaviours for just bevy_editor_pls and bevy-inspector-egui, and I think this is a slightly cleaner way of achieving that goal.