[Tagging] musical_instrument tag for publicly available musical instruments

[Marc Gemis]

Besides the arguments from Martin,

how do you differentiate the "rental" in a bar, where you can only
play on the instrument, and not take it away from the room/building
from a real rental company that deliver instruments to play somewhere
else ?

> musical_instrument:sales=*
> musical_instrument:rental=*
> musical_instrument:repair=*
> musical_instrument:parts=*
> https://wiki.openstreetmap.org/wiki/Tag:shop%3Dmusical_instrument
>
> I case of the bars,
> it could be
> amenity=bar
> musical_instrument:rental=piano
> fee:piao=no @ customers
> https://wiki.openstreetmap.org/wiki/Key:fee