message: docs: update migration documentation
diff: @@ -35,6 +35,8 @@ one object.
  with `Box` so you can use pseudo style props, like `_hover`, `_active` in any
  Chakra components.
  +**Dropped Support of IE11:** We've dropped support of `IE11` [reason](https://github.com/chakra-ui/chakra-ui/pull/2762)
  +
  ---
  ## Upgrade steps
  