[talk-ch] Small wiki changes

After discussion at the Zürcher Stammtisch yesterday, I've made two modifications to the wiki:

+ changed the instructions for bicycle routes to indicate to use route=mtb for mountain bike routes (and I've tried to fix the relevant relations) ( http://wiki.openstreetmap.org/wiki/EN:Switzerland/CycleNetwork )

+ added sign 2.14 to Switzerland specific tagging, this is common at least in German speaking Switzerland ( http://wiki.openstreetmap.org/wiki/EN:CH:Map_Features )

Naturally if anybody really disagrees, we can revert and discuss. I've just changed the English and the German entries, leaving the French and non-existant Italian version to somebody else.

Simon