updated documentation

Author: MattFromRVA

documentation/SA1642.md

@@ -96,6 +96,23 @@ private Customer()
 }
 ```
 
+The `<para>` tag can be used within the `<summary>` tag to structure the text. 
+For example:
+
+```csharp
+/// <summary>
+/// <para>
+/// Initializes a new instance of the <see cref="Customer"/> class.
+/// </para>
+/// <para>
+/// Additional information can be included in subsequent paragraphs.
+/// </para>
+/// </summary>
+public Customer()
+{
+}
+```
+
 ## How to fix violations
 
 To fix a violation of this rule, edit the summary text for the constructor as described above.