Clarify record type definition with primary constructors (#48110)

Author: gewarren

docs/ai/quickstarts/structured-output.md

@@ -93,10 +93,12 @@ Complete the following steps to create a console app that connects to the `gpt-4
 
 1. And instead of requesting just the analyzed enumeration value, you can request the text response along with the analyzed value.
 
-   Define a record type to contain the text response and analyzed sentiment:
+   Define a [record type](../../csharp/language-reference/builtin-types/record.md) to contain the text response and analyzed sentiment:
 
    :::code language="csharp" source="./snippets/structured-output/Program.cs" id="InputOutputRecord":::
 
+   (This record type is defined using [primary constructor](../../csharp/programming-guide/classes-and-structs/instance-constructors.md#primary-constructors) syntax. Primary constructors combine the type definition with the parameters necessary to instantiate any instance of the class. The C# compiler generates public properties for the primary constructor parameters.)
+
    Send the request using the record type as the type argument to `GetResponseAsync<T>`:
 
    :::code language="csharp" source="./snippets/structured-output/Program.cs" id="RecordRequest":::