Add .NET links (#20)

Author: codebrain

README.md

@@ -13,3 +13,14 @@ ECS Logging - Common resources and issues for the language specific ECS loggers
 * [JavaScript](https://github.com/elastic/ecs-logging-js)
   * [Winston](https://github.com/elastic/ecs-logging-js/tree/master/loggers/winston)
   * [Morgan](https://github.com/elastic/ecs-logging-js/tree/master/loggers/morgan)
+
+## APM
+
+* [.NET](https://github.com/elastic/ecs-dotnet)
+  * [Serilog Enricher](https://github.com/elastic/ecs-dotnet/tree/master/src/Elastic.Apm.SerilogEnricher)
+  * [NLog Enricher](https://github.com/elastic/ecs-dotnet/tree/master/src/Elastic.Apm.NLog)
+  
+## Benchmarking
+
+* [.NET](https://github.com/elastic/ecs-dotnet)
+  * [BenchmarkDotNet Exporter](https://github.com/elastic/ecs-dotnet/tree/master/src/Elastic.CommonSchema.BenchmarkDotNetExporter)