Add SendGrid helpers import statement

Author: craigshoemaker

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

@@ -35,6 +35,10 @@ The following example shows a [C# function](functions-dotnet-class-library.md) t
 ### Synchronous
 
 ```cs
+using SendGrid.Helpers.Mail;
+
+...
+
 [FunctionName("SendEmail")]
 public static void Run(
     [ServiceBusTrigger("myqueue", Connection = "ServiceBusConnection")] Message email,
@@ -61,6 +65,10 @@ public class OutgoingEmail
 ### Asynchronous
 
 ```cs
+using SendGrid.Helpers.Mail;
+
+...
+
 [FunctionName("SendEmail")]
 public static async void Run(
  [ServiceBusTrigger("myqueue", Connection = "ServiceBusConnection")] Message email,