Corrected SA1604 documentation to include a relevant example

#3848

Author: bjornhellander

documentation/SA1604.md

@@ -29,12 +29,10 @@ A violation of this rule occurs when the element documentation is missing a `<su
 
 To fix a violation of this rule, add and fill-in a `<summary>` tag for the element, containing a description of the element.
 
-The following example shows a class containing invalid Xml within its documentation header. The closing tag for the `<summary>` node is invalid.
+The following example shows a class containing a documentation header without a summary.
 
 ```csharp
-/// <summary>
-/// Represents a customer in the database.
-/// </summary>
+/// <remarks>A remark.</remarks>
 public class Customer
 {
 }