Added new method to type summary (#2365)

Author: Ron Petrusha

xml/System.IO.Compression/ZipFileExtensions.xml

@@ -44,14 +44,16 @@
   
  To use the extension methods, you must reference the `System.IO.Compression.FileSystem` assembly in your project. The `System.IO.Compression.FileSystem` assembly is not available in [!INCLUDE[win8_appname_long](~/includes/win8-appname-long-md.md)] apps. Therefore, the <xref:System.IO.Compression.ZipFileExtensions> and <xref:System.IO.Compression.ZipFile> classes (both of which are in the `System.IO.Compression.FileSystem` assembly) are not available in [!INCLUDE[win8_appname_long](~/includes/win8-appname-long-md.md)] apps. In [!INCLUDE[win8_appname_long](~/includes/win8-appname-long-md.md)] apps, you work with compressed files by using the methods in <xref:System.IO.Compression.ZipArchive>, <xref:System.IO.Compression.ZipArchiveEntry>, <xref:System.IO.Compression.DeflateStream>, and <xref:System.IO.Compression.GZipStream>.  
   
- The <xref:System.IO.Compression.ZipFileExtensions> class contains three methods that extend <xref:System.IO.Compression.ZipArchive>:  
+ The <xref:System.IO.Compression.ZipFileExtensions> class contains four methods that extend <xref:System.IO.Compression.ZipArchive>:  
   
 -   <xref:System.IO.Compression.ZipFileExtensions.CreateEntryFromFile%28System.IO.Compression.ZipArchive%2CSystem.String%2CSystem.String%29>  
   
 -   <xref:System.IO.Compression.ZipFileExtensions.CreateEntryFromFile%28System.IO.Compression.ZipArchive%2CSystem.String%2CSystem.String%2CSystem.IO.Compression.CompressionLevel%29>  
   
 -   <xref:System.IO.Compression.ZipFileExtensions.ExtractToDirectory%28System.IO.Compression.ZipArchive%2CSystem.String%29>  
-  
+
+-   <xref:System.IO.Compression.ZipFileExtensions.ExtractToDirectory%28System.IO.Compression.ZipArchive%2CSystem.String%2CSystem.Boolean%29>  
+
  The <xref:System.IO.Compression.ZipFileExtensions> class contains two methods that extend <xref:System.IO.Compression.ZipArchiveEntry>:  
   
 -   <xref:System.IO.Compression.ZipFileExtensions.ExtractToFile%28System.IO.Compression.ZipArchiveEntry%2CSystem.String%29>