feat: add help icon to sidebar linking to documentation

- Add HelpButton component with question mark icon
- Integrate help button into sidebar next to settings button
- Link opens documentation in new tab when clicked
- Maintain consistent styling with existing sidebar buttons
- Improve user accessibility to documentation resources

app/components/ui/SettingsButton.tsx

@@ -16,3 +16,20 @@ export const SettingsButton = memo(({ onClick }: SettingsButtonProps) => {
     />
   );
 });
+
+interface HelpButtonProps {
+  onClick: () => void;
+}
+
+export const HelpButton = memo(({ onClick }: HelpButtonProps) => {
+  return (
+    <IconButton
+      onClick={onClick}
+      icon="i-ph:question"
+      size="xl"
+      title="Help & Documentation"
+      data-testid="help-button"
+      className="text-[#666] hover:text-bolt-elements-textPrimary hover:bg-bolt-elements-item-backgroundActive/10 transition-colors"
+    />
+  );
+});