Add cookbook entry

Author: XWB

Resources/doc/index.md

@@ -23,3 +23,4 @@ Cookbook Entries
 * [Suppressing server errors](cookbook/suppress-server-errors.md)
 * [Hints on result hydration](cookbook/hints-on-result-hydration.md)
 * [Multi type search](cookbook/multi-type-search.md)
+* [Attachments Handling](cookbook/attachments.md)