Added maintainer required message.

Author: nblumhardt

README.md

@@ -1,2 +1,5 @@
-# serilog-sinks-xamarin
-A Serilog sink that writes events to Xamarin mobile targets
+# Serilog.Sinks.Xamarin
+
+A Serilog sink that writes events to Xamarin mobile targets.
+
+**This sub-project needs an active maintainer.** Without an owner/owners who both have the knowledge and software licenses required to support Xamarin, we've been unable to move this forwards. Please raise an issue on the Serilog tracker if this is you :-)