Updated the ReadMe

Author: softwaresalt

README.md

@@ -25,6 +25,16 @@ dotnet build
 dotnet test ./test/System.CommandLine.Parser.Tests.csproj
 ```
 
+To reference in your own .NET Core project:
+
+
+```bash
+using System.CommandLine;
+
+Parser parser = new Parser();
+```
+
+
 ## Contributions
 
 I always greatly appreciate feedback and bug reports. To file a bug, please use GitHub's issue system.