Add support for Events (#23)

* event wip...

* Add support for 'event'

* event example

src/ProxyInterfaceSourceGenerator/ProxyInterfaceCodeGenerator.cs

@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Text;
 using ProxyInterfaceSourceGenerator.FileGenerators;