Add readme

README.md

@@ -1,9 +1,50 @@
-Work in Progress
+Elastic APM extensions for multiple .NET libraries.
+## Features
 
-## Getting Started
+- Messaging
+  - [X] [MassTransit](#masstrasit)
+  - [ ] Azure Service Bus
 
-## Features
+- GraphQL
+  - [X] [HotChocolate](#hotchocolate)
+
+- Storage
+  - [ ] Azure Blob Storage
+
+### MassTransit
+```csharp
+public static IHostBuilder CreateHostBuilder(string[] args) =>
+    Host.CreateDefaultBuilder(args)
+        .ConfigureWebHostDefaults(webBuilder =>
+        {
+            webBuilder.UseStartup<Startup>();
+        })
+        .UseElasticApm(
+            // Add additional diagnostic subscribers e.g. AspNetCore, Http, etc
+            new MassTransitDiagnosticsSubscriber());
+```
+
+The following events from the [MassTransit DiagnosticSource](https://masstransit-project.com/advanced/monitoring/diagnostic-source.html) are instrumented:
+- `Transport.Send` 
+- `Transport.Receive`
+
+### HotChocolate
+HotChocolate by default is not emitting diagnostic events, but has the infrastructure to instrument each request.
+```csharp
+public class Startup
+{
+    public void ConfigureServices(IServiceCollection services)
+    {
+        // Add your services
 
+        // Add HotChocolate GraphQL Server
+        services
+            .AddGraphQLServer()
+            .AddQueryType<Query>()
+            .AddObservability(); // Register instrumentation for Elastic APM
+    }
+}
+```
 ## Community
 
 This project has adopted the code of conduct defined by the [Contributor Covenant](https://contributor-covenant.org/)