message: docs: add menu isLazy props
diff: @@ -197,6 +197,31 @@ component.
  </Menu>
  ```
  +### Lazily mounting MenuItem
  +
  +By default, the `Menu` component renders all `MenuItem` to the DOM, meaning that invisible menu items are still rendered but are hidden by styles.
  +
  +If you want to defer rendering of each menu item until that menu is open, you can use the `isLazy` prop. This is useful if your menus require heavy performance, or make network calls on mount that should only happen when the component is displayed.
  +
  +```jsx live=false
  +<Menu isLazy>
  + <MenuButton size="sm" colorScheme="teal">
  + Open menu
  + </MenuButton>
  + <MenuList>
  + {/* initially mounted */}
  + <MenuItem>Menu 1</MenuItem>
  + {/* initially mounted */}
  + <MenuItem>New Window</MenuItem>
  + {/* initially mounted */}
  + <MenuItem>Open Closed Tab</MenuItem>
  + {/* initially mounted */}
  + <MenuItem>Open File</MenuItem>
  + </MenuList>
  + <MenuList>
  +</Menu>
  +```
  +
  ### Rendering menu in a portal
  To render menus in a portal, import the `Portal` component and wrap the
  @@ -307,6 +332,7 @@ options. Use the `MenuOptionGroup` and `MenuItemOption` components.
  | closeOnBlur | `boolean` | `true` | If `true`, the menu will close on outside click or blur |
  | closeOnSelect | `boolean` | `true` | If `true`, the menu will close on menu item select |
  | placement | `PopperJS.placement` | | The placement of the `MenuList` |
  +| isLazy | `boolean` | | If `true`, the MenuItem will render until the menu is open. |
  ### MenuButton Props
  