[Tagging] Improving 'bicycle rental'-tagging

[Pieter Vander Vennet]

Hi all,

I'm currently working on bicycle rental.

A tag for this already exists, but can use some updates and more nuance 
- as many types of bicycle rental do exist nowadays.

I have created a small proposal on the [relevant talk 
page](https://wiki.openstreetmap.org/wiki/Talk:Tag:amenity%3Dbicycle_rental#Tagging_the_different_types_of_bicycle_rental)

This is just a proposal, so it is probably imperfect and there might be 
a few forms of bicycle rental that I'm not aware of, so please add your 
thoughts on them!

Kind regards,
Pieter