Revert "No need to use extension bundles with C# libraries."

This reverts commit fbe38fe.

Author: mcollier

articles/azure-functions/functions-bindings-register.md

@@ -59,6 +59,9 @@ If you use `Install-Package` to reference a binding, you don't need to use [exte
 
 ## <a name="vs-code"></a> C# class library with Visual Studio Code
 
+> [!NOTE]
+> We recommend using [extension bundles](#extension-bundles) to have Functions automatically install a compatible set of binding extension packages. 
+
 In **Visual Studio Code**, install packages for a C# class library project from the command prompt using the [dotnet add package](https://docs.microsoft.com/dotnet/core/tools/dotnet-add-package) command in the .NET Core CLI. The following example demonstrates how you add a  binding:
 
 ```terminal