Add info about new release 3.9.2 (#2440)

* Add info about new release 3.9.2

* chore: update changelog

Co-authored-by: Divine <48183131+divine@users.noreply.github.com>

CHANGELOG.md

@@ -3,6 +3,14 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [3.9.2] - 2022-09-01
+
+### Addded 
+- Add single word name mutators [#2438](https://github.com/jenssegers/laravel-mongodb/pull/2438) by [@RosemaryOrchard](https://github.com/RosemaryOrchard) & [@mrneatly](https://github.com/mrneatly).
+
+### Fixed
+- Fix stringable sort [#2420](https://github.com/jenssegers/laravel-mongodb/pull/2420) by [@apeisa](https://github.com/apeisa).
+
 ## [3.9.1] - 2022-03-11
 
 ### Added