Add missing documentation for interceptors (#5279)

Closes #4417
Closes #4726

Author: roji

entity-framework/core/logging-events-diagnostics/interceptors.md

@@ -3428,9 +3428,9 @@ This validation can be disabled if necessary. For example:
 
 GitHub Issue: [#23719](https://github.com/dotnet/efcore/issues/23719). This feature was contributed by [@Giorgi](https://github.com/Giorgi). Many thanks!
 
-The `CommandEventData` supplied to diagnostics sources and interceptors now contains an enum value indicating which part of EF was responsible for creating the command. This can be used as a filter in the diagnostics or interceptor. For example, we may want an interceptor that only applies to commands that come from `SaveChanges`:
+The <xref:Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData> supplied to diagnostics sources and interceptors now contains a <xref:Microsoft.EntityFrameworkCore.Diagnostics.CommandSource> enum value indicating which part of EF was responsible for creating the command. This can be used to filter interceptor behavior, for example to only intercept commands originating from `SaveChanges`:
 
-<!--
+```csharp
 public class CommandSourceInterceptor : DbCommandInterceptor
 {
     public override InterceptionResult<DbDataReader> ReaderExecuting(
@@ -3446,8 +3446,7 @@ public class CommandSourceInterceptor : DbCommandInterceptor
         return result;
     }
 }
--->
-[!code-csharp[Interceptor](../../../../samples/core/Miscellaneous/NewInEFCore6/CommandSourceSample.cs?name=Interceptor)]
+```
 
 This filters the interceptor to only `SaveChanges` events when used in an application which also generates migrations and queries. For example:
 
@@ -3462,6 +3461,8 @@ FROM [Customers]
 WHERE @@ROWCOUNT = 1 AND [Id] = scope_identity();
 ```
 
+For more information, see [Filtering by command source](xref:core/logging-events-diagnostics/interceptors#filtering-by-command-source).
+
 ### Better temporary values handling
 
 GitHub Issue: [#24245](https://github.com/dotnet/efcore/issues/24245).

entity-framework/core/what-is-new/ef-core-6.0/whatsnew.md

@@ -40,7 +40,6 @@ public static async Task Main()
         await HasConversionSample.Can_set_value_converter_type_using_generic_method();
         MinimalApiSample.Add_a_DbContext_and_provider();
         await ToInMemoryQuerySample.Can_query_keyless_types_from_in_memory_database();
-        await CommandSourceSample.Interceptors_get_the_source_of_the_command();
         await ScaffoldingSample.Reverse_engineer_from_database();
         await ManyToManyConfigurationSample.Many_to_many_relationships_may_need_less_configuration();
         await ConvertNullsSample.Value_converters_can_convert_nulls();