Points of interests on the map and info pages

[aajanki]

Implement the possibility to add new locations on the map and show information related to the location on a separate page.

Location data could be in the same format as data/stages.json. There should be one info page for each location.

[deiga]

Locations have a description field which can be used for the information, if this is not an optimal solution an implementation of embedded information documents can be achieved

[aajanki]

I think a description field is enough for now. A separate issue can be opened if there is need for something else later on.