Fix PipelineNameComparer example in documentation snippet

Addresses App-vNext#1926

In the Complex Pipeline Keys documenation example:

https://www.pollydocs.org/advanced/dependency-injection.html#complex-pipeline-keys

PipelineNameComparer.GetHashCode takes the InstanceName into account, but shouldn't. This fixes that line in the documentation.

src/Snippets/Docs/DependencyInjection.cs

@@ -225,7 +225,7 @@ public sealed class PipelineNameComparer : IEqualityComparer<MyPipelineKey>
     {
         public bool Equals(MyPipelineKey x, MyPipelineKey y) => x.PipelineName == y.PipelineName;
 
-        public int GetHashCode(MyPipelineKey obj) => (obj.PipelineName, obj.InstanceName).GetHashCode();
+        public int GetHashCode(MyPipelineKey obj) => obj.PipelineName.GetHashCode();
     }
 
     #endregion