Add release notes for 1.10.5

Author: mxsasha

Changelog.md

@@ -20,10 +20,16 @@ _Compared to the latest 1.10 release._
 
 - ...
 
+## 1.10.5
+
+- Fixed an issue in 1.10.x where [DNSSEC test could return false negatives](https://github.com/internetstandards/Internet.nl/issues/1869)
+  due to an interaction between cached responses and the CD and AD flags.
+- Added news post.
+
 ## 1.10.4
 
 - Updated our security.txt.
-- Updated Django
+- Updated Django version.
 
 ## 1.10.3