Improve S2094: Add exceptions (#1575)

* Update VB description

* Add Exceptions section

rules/S2094/csharp/rule.adoc

@@ -18,6 +18,22 @@ public interface IEmpty
 }
 ----
 
+== Exceptions
+
+Partial classes are ignored entirely, as they are often used with Source Generators.
+Subclasses of System.Exception are ignored, as even an empty Exception class can provide useful information by its type name alone.
+Subclasses of System.Attribute are ignored, as well as classes which are annotated with attributes.
+Subclasses of generic classes are ignored, as even when empty they can be used for type specialization.
+Subclasses of certain framework types - like the PageModel class used in ASP.NET Core Razor Pages - are also ignored.
+
+----
+using Microsoft.AspNetCore.Mvc.RazorPages;
+
+public class EmptyPageModel: PageModel // Compliant - an empty PageModel can be fully functional, the C# code can be in the cshtml file
+{ 
+}
+----
+
 ifdef::env-github,rspecator-view[]
 
 '''

rules/S2094/vbnet/rule.adoc

@@ -1,4 +1,4 @@
-include::../description.adoc[]
+There is no good excuse for an empty class. If it's being used simply as a common extension point, it should be replaced with an ``++Interface++``. If it was stubbed in as a placeholder for future development it should be fleshed-out. In any other case, it should be eliminated.
 
 == Noncompliant Code Example
 
@@ -18,6 +18,21 @@ Public Interface IEmpty
 End Interface
 ----
 
+== Exceptions
+
+Partial classes are ignored entirely, as they are often used with Source Generators.
+Subclasses of System.Exception are ignored, as even an empty Exception class can provide useful information by its type name alone.
+Subclasses of System.Attribute are ignored, as well as classes which are annotated with attributes.
+Subclasses of generic classes are ignored, as even when empty they can be used for type specialization.
+Subclasses of certain framework types - like the PageModel class used in ASP.NET Core Razor Pages - are also ignored.
+----
+Imports Microsoft.AspNetCore.Mvc.RazorPages
+
+Public Class EmptyPageModel ' Compliant - an empty PageModel can be fully functional, the VB code can be in the vbhtml file
+    Inherits PageModel
+End Class
+----
+
 ifdef::env-github,rspecator-view[]
 
 '''