Render big bicycle parking bigger

[Florimondable]

From my trip in Netherlands, it was difficult to find on the map the big bicycle parking facility like the ones in train station or in the city center, see Utrecht for instance https://www.cyclosm.org/#map=16/52.0914/5.1135/cyclosm

We could render bicycle parking with a lot of capacity (> 100 ? > 50 ?) with a bigger icon, or/and at lower zoom.