add forward slashes to correct URL in readme
add forward slashes to correct URL in readme

webmasterkai/signalk-server-node,SignalK/signalk-server-node,SignalK/signalk-server-node,sbender9/signalk-server-node,webmasterkai/signalk-server-node,sbender9/signalk-server-node,SignalK/signalk-server-node,SignalK/signalk-server-node,webmasterkai/signalk-server-node,sbender9/signalk-server-node