Adding #1125 to changelog

Author: batzen

Changelog.md

@@ -7,6 +7,7 @@
   - [#1133](../../issues/1133) - Fixing binding path to attached property for simplified ControlTemplates (thanks @dcm99)
   - [#1134](../../issues/1134) - Selected Tab on first render has a black border
   - [#1135](../../issues/1135) - Black line between Ribbon and Window (when using a colorful theme)
+  - [#1125](../../issues/1125) - BackStage Back Button doesn't have an accessibility text.
 
 ## 10.0.0