Simplify and document usage of useInteraction and useModifierKeyPressed

[axelboc]

Following #1475, I'm documenting the newly exported useInteraction and useModifierKeyPressed hooks.

I'm also taking the opportunity to do a bit of a refactoring now, to avoid a breaking change down the line:

• InteractionEntry (the second parameter of useInteraction) becomes InteractionConfig
• We no longer need to cast the modifierKey prop to an array before calling useInteraction and useMdifierKeyPressed (thus removing the need for getModifierKeyArray)
• I'm introducing an Interaction class internally to encapsulate the casting of the modiferKeys and buttons arrays and the logic of whether an interaction "matches" a mouse event.

[loichuder]

Nice !