Adds AI explain branch changes feature

Author: vicenter-gitkraken

gitkraken-desktop/gkd-gitkraken-ai.md

@@ -164,6 +164,11 @@ You can then use the AI button again to generate a revised commit message.
 
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+## Explain Branch Changes with AI 
+
+Right-click any branch and select **Explain Branch Changes** to get a summary of all changes on that branch.
+
+***
 ## AI-Powered Merge Conflict Resolution
 
 Resolve merge conflicts faster with GitKraken AI.