Docs: `g:iced#nrepl#ns#refresh_after_fn` example uses `refresh_before_fn` var name

[stevejmp]

The example usage for g:iced#nrepl#ns#refresh_after_fn uses the wrong variable name:

                                             *g:iced#nrepl#ns#refresh_after_fn*
g:iced#nrepl#ns#refresh_after_fn
  A qualified function name to evaluate after |:IcedRefresh|.
  The function should be zero-arity.
  E.g. >
  let g:iced#nrepl#ns#refresh_before_fn = 'user/start'
<
  Default value is `''`. (Not to evaluate)

It should be

  E.g. >
  let g:iced#nrepl#ns#refresh_after_fn = 'user/start'
<