define Generic host (#17849)

* define Generic host

* define Generic host

* define Generic host

Author: Rick-Anderson

aspnetcore/fundamentals/host/generic-host.md

@@ -12,7 +12,7 @@ uid: fundamentals/host/generic-host
 
 ::: moniker range=">= aspnetcore-3.0 <= aspnetcore-3.1"
 
-The ASP.NET Core templates create a .NET Core Generic Host (<xref:Microsoft.Extensions.Hosting.HostBuilder>).
+The ASP.NET Core templates create a .NET Core Generic Host, <xref:Microsoft.Extensions.Hosting.HostBuilder>.
 
 ## Host definition
 
@@ -34,7 +34,7 @@ The host is typically configured, built, and run by code in the `Program` class.
 * Calls a `CreateHostBuilder` method to create and configure a builder object.
 * Calls `Build` and `Run` methods on the builder object.
 
-The ASP.NET Core web templates generate the following code to create a host:
+The ASP.NET Core web templates generate the following code to create a Generic Host:
 
 ```csharp
 public class Program
@@ -53,7 +53,7 @@ public class Program
 }
 ```
 
-The following code creates a non-HTTP workload with a `IHostedService` implementation added to the DI container.
+The following code creates a Generic Host using non-HTTP workload. The `IHostedService` implementation is added to the DI container:
 
 ```csharp
 public class Program
@@ -83,6 +83,8 @@ public static IHostBuilder CreateHostBuilder(string[] args) =>
         });
 ```
 
+The preceding code is generated by the ASP.NET Core templates.
+
 If the app uses Entity Framework Core, don't change the name or signature of the `CreateHostBuilder` method. The [Entity Framework Core tools](/ef/core/miscellaneous/cli/) expect to find a `CreateHostBuilder` method that configures the host without running the app. For more information, see [Design-time DbContext Creation](/ef/core/miscellaneous/cli/dbcontext-creation).
 
 ## Default builder settings