Update RPi installation guide (#453)
Update RPi installation guide (#453)

Add how to configure, via Admin UI, real input from NMEA interfaces and the signalk-to-nmea0183 plug in.
SignalK/signalk-server-node,webmasterkai/signalk-server-node,SignalK/signalk-server-node,webmasterkai/signalk-server-node,SignalK/signalk-server-node,webmasterkai/signalk-server-node,SignalK/signalk-server-node