Changelog entry for required global search option in grammar rules

Author: yuryleb

CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file. For change
 ## master
 
 - Added some abbreviations in German, Hebrew, Hungarian, Slovenian, and Ukrainian. [#226](https://github.com/Project-OSRM/osrm-text-instructions/pull/226)
+- Global search option is now required for all grammar rules. [#228](https://github.com/Project-OSRM/osrm-text-instructions/pull/228)
 
 ## 0.12.0 2018-02-26