updated "Additional notes"

extension/ui/pages/help.html

@@ -42,6 +42,8 @@
 						The context menu also allows activating automatic page saving of a tab, unpinned tabs, or all tabs.</li>
 					<li>With auto-save active, pages will be automatically saved every time after being loaded. The period of time to wait before
 						saving the page can be configured in the options page.</li>
+					<li>Check the option "auto-save on page unload" in the options page to auto-save the page before being unloading instead
+						of after being loaded.</li>
 				</ul>
 			</li>
 			<li>