Add DI video link

docs/faq/Commands.md

@@ -51,7 +51,7 @@ Service is often used to hold data externally, so that they will
 persist throughout execution. Think of it like a chest that holds 
 whatever you throw at it that won't be affected by anything unless 
 you want it to. Note that you should also learn Microsoft's 
-implementation of [Dependency Injection] before proceeding, as well 
+implementation of [Dependency Injection] ([video]) before proceeding, as well 
 as how it works in [Discord.NET](../guides/commands/commands.md#usage-in-modules).
 
 A brief example of service and dependency injection can be seen below.
@@ -59,6 +59,7 @@ A brief example of service and dependency injection can be seen below.
 [!code-csharp[DI](samples/commands/DI.cs)]
 
 [Dependency Injection]: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/dependency-injection
+[video]: https://www.youtube.com/watch?v=QtDTfn8YxXg
 
 ## I have a long-running Task in my command, and Discord.NET keeps saying that a `MessageReceived` handler is blocking the gateway. What gives?