Add changelog item

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

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
+v 8.2.0 (unreleased)
+  - Show last project commit to default branch on project home page
+
 v 8.1.0 (unreleased)
   - Fix error preventing displaying of commit data for a directory with a leading dot (Stan Hu)
   - Speed up load times of issue detail pages by roughly 1.5x