Add note to the summary of important changes

site/docs/4.2/content/reboot.md

@@ -206,6 +206,7 @@ Various form elements have been rebooted for simpler base styles. Here are some
 - `<label>`s are set to `display: inline-block` to allow `margin` to be applied.
 - `<input>`s, `<select>`s, `<textarea>`s, and `<button>`s are mostly addressed by Normalize, but Reboot removes their `margin` and sets `line-height: inherit`, too.
 - `<textarea>`s are modified to only be resizable vertically as horizontal resizing often "breaks" page layout.
+- `<button>`s and `<input>` button elements have `cursor: pointer` when `:not(:disabled)`.
 
 These changes, and more, are demonstrated below.