📝 Add a focus-ring window rule for Niri

Author: make-42

src/content/docs/installation-on-linux.mdx

@@ -272,6 +272,7 @@ Else, the menu will not float above other windows.
 window-rule {
     match title="Kando Menu"
     open-floating true
+    focus-ring { off; }
     border { off; }
     shadow { off; }
 }