Improve linking to a single location

[karussell]

Currently we can link to a location by using a single point argument: https://graphhopper.com/maps/?point=berlin and it will already do the geocoding automatically.

Still, there are important improvements:

• zoom closer and zoom also when a location is selected from the suggestion (via mouse or ENTER)
• avoid that the first point is remove so that destinations can be specified: https://graphhopper.com/maps/?point=&point=berlin

[flaun]

would be nice to have this!
very often I use graphhopper maps just by showing me a single point without a route.
thx for your work!