Consider tram lines for routing

[rheyse]

Tram lines are annoying and dangerous for cyclists as the wheels might get stuck in the tram line. railway=tram is the key=tag combination that indicates tram lines. The problem is that in OSM, these are used on a separate line (not the street) and we therefore cannot differentiate between tram lines that are embedded in the street (dangerous) and tram lines that are separate from the street (we don't care). See https://wiki.openstreetmap.org/wiki/Trams#Embedded_tracks