Documentation: how to set up this project

[extua]

• You will need: a MongoDB instance, clone this repo, npm install
• Download files from api.freifunk.net
• Create config file, see Data loading: read parameters from a config file #51
• Download json_adder binaries from release, see Data-loading: create release binary #34
• Run import
• Start MongoDB
• npm start
• navigate to localhost/static