proposed changes to English contribution guide
proposed changes to English contribution guide

The changes are mostly editorial (I guess/hope my changes are better).

"First line" is ambiguous, so I removed it.
JKennedy24/Xamarin.Forms.GoogleMaps,amay077/Xamarin.Forms.GoogleMaps,JKennedy24/Xamarin.Forms.GoogleMaps,quesera2/Xamarin.Forms.GoogleMaps