fix: Update 1.21 to match output (#819)

Fixes #789

Author: BenjaminMichaelis

src/Chapter01.Tests/Listing01.21.Tests.cs

@@ -11,7 +11,7 @@ public void Main_InputInigoMontoya_WriteLastFirst()
 @"Hey you!
 Enter your first name: <<Inigo
 >>Enter your last name: <<Montoya
->>Your full name is Montoya, Inigo.";
+>>Your full name is Inigo Montoya.";
 
         IntelliTect.TestTools.Console.ConsoleAssert.Expect(
             expected, CommentSamples.Main);

src/Chapter01/Listing01.21.CommentingYourCode.cs

@@ -19,7 +19,7 @@ public static void Main()
         /* Display a greeting to the console 
           using composite formatting. */
 
-        Console.WriteLine("Your full name is {1}, {0}.", 
+        Console.WriteLine("Your full name is {0} {1}.",
             firstName, lastName);
         // This is the end
         // of the program listing