Add changelog items

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

CHANGELOG

@@ -20,6 +20,9 @@ v 8.0.0 (unreleased)
   - Move dashboard activity to separate page
   - Improve performance of git blame
   - Limit content width to 1200px for most of pages to improve readability on big screens
+  - Fix 500 error when submit project snippet without body
+  - Improve search page usability
+  - Bring more UI consistency in way how projects, snippets and groups lists are rendered
 
 v 7.14.1 (unreleased)
   - Only include base URL in OmniAuth full_host parameter (Stan Hu)