[Haml] Add a changelog entry about the previous commit.

doc-src/HAML_CHANGELOG.md

@@ -3,6 +3,11 @@
 * Table of contents
 {:toc}
 
+## 2.2.5
+
+* Got rid of trailing whitespace produced when opening a conditional comment
+  (thanks to [Norman Clarke](http://blog.njclarke.com/)).
+
 ## [2.2.4](http://github.com/nex3/haml/commit/2.2.4)
 
 * Allow `end` to be used for silent script when it's followed by code.