fix: Prefer flipping submenu to left side over to the bottom

Author: frankieyan

src/menu/menu.stories.mdx

@@ -126,7 +126,7 @@ be changed by passing `modal={false}` to `<MenuList>`
 
 You may nest the `<SubMenu>` component within `<Menu>` to create submenus.
 
-On smaller viewports where there isn't enough space to render the submenu on the side, it will be rendered under its parent menu item instead.
+On smaller viewports where there isn't enough space to render the submenu on either side, it will be rendered under its parent menu item instead.
 
 <Canvas>
     <Story

src/menu/menu.tsx

@@ -172,7 +172,7 @@ const MenuList = React.forwardRef<HTMLDivElement, MenuListProps>(function MenuLi
                 className={classNames('reactist_menulist', exceptionallySetClassName)}
                 getAnchorRect={getAnchorRect ?? undefined}
                 modal={modal}
-                flip={flip ?? (isSubMenu ? 'bottom' : undefined)}
+                flip={flip ?? (isSubMenu ? 'left bottom' : undefined)}
             />
         </Portal>
     ) : null