Update CHANGELOG.md

Author: dimirc

CHANGELOG.md

@@ -11,6 +11,7 @@ All notable changes to this project will be documented in this file.
 - Avoid setting activeItem on mouseenter to improve performance [#1211](https://github.com/angular-ui/ui-select/pull/1211)
 
 ### Fixed
+- Position dropdown UP or DOWN correctly depending on the available space [#1212](https://github.com/angular-ui/ui-select/pull/1212)
 - Scroll to selected item [#976](https://github.com/angular-ui/ui-select/issues/976)
 - Change `autocomplete='off'` to `autocomplete='false'` [#1210](https://github.com/angular-ui/ui-select/pull/1210)
 - Fix to work correctly with debugInfoEnabled(false) [#1131](https://github.com/angular-ui/ui-select/pull/1131)