Changelog entry for required global search option in grammar rules

Author: yuryleb

CHANGELOG.md

@@ -6,6 +6,7 @@ All notable changes to this project will be documented in this file. For change
 - Added a Finnish localization. [#239](https://github.com/Project-OSRM/osrm-text-instructions/pull/239)
 - Added a Korean localization. [#243](https://github.com/Project-OSRM/osrm-text-instructions/pull/243)
 - Updated translations in Simplified Chinese. [#233](https://github.com/Project-OSRM/osrm-text-instructions/pull/233)
+- Global search option is now required for all grammar rules. [#228](https://github.com/Project-OSRM/osrm-text-instructions/pull/228)
 
 ## 0.13.0 2018-04-11