Added missing step in text (#20141)

* Added missing step in text

Added important instructional text "From the dropdown boxes, select .NET Core and ASP.NET Core 3.1". I missed this step in the tutorial because it was not instructed in the text. Later on I had to go back and recreate my project because I missed it.

* Update start-mvc.md

Co-authored-by: Rick Anderson <3605364+Rick-Anderson@users.noreply.github.com>

Author: leastofthese23

aspnetcore/tutorials/first-mvc-app/start-mvc.md

@@ -51,15 +51,15 @@ At the end, you have an app that can manage and display movie data.
 
 * From the Visual Studio select **Create a new project**.
 
-* Select **ASP.NET Core Web Application** and then select **Next**.
+* Select **ASP.NET Core Web Application** > **Next**.
 
 ![new ASP.NET Core Web Application](start-mvc/_static/np_2.1.png)
 
 * Name the project **MvcMovie** and select **Create**. It's important to name the project **MvcMovie** so when you copy code, the namespace will match.
 
   ![new ASP.NET Core Web Application](start-mvc/_static/config.png)
 
-* Select **Web Application(Model-View-Controller)**, and then select **Create**.
+* Select **Web Application(Model-View-Controller)**. From the dropdown boxes, select **.NET Core** and **ASP.NET Core 3.1**, then select **Create**.
 
 ![New project dialog, .NET Core in left pane, ASP.NET Core web ](start-mvc/_static/new_project30.png)