message: [docs] Fix DateFnsAdapter import docs typo
  * Fix DateFnsAdapter import
  The Adapter comes from  "@material-ui/pickers/adapter/date-fns";  instead of '@material-ui-pickers/adapter/date-fns';
  * " fix
diff: @@ -17,14 +17,14 @@ import { CODESANDBOX_EXAMPLE_ID } from '_constants';
  ```jsx
  import React, { useState } from 'react';
  -import DateFnsUtils from '@material-ui-pickers/adapter/date-fns'; // choose your lib
  +import DateFnsAdapter from '@material-ui/pickers/adapter/date-fns'; // choose your lib
  import { DatePicker, TimePicker, DateTimePicker, LocalizationProvider } from '@material-ui/pickers';
  function App() {
  const [selectedDate, handleDateChange] = useState(new Date());
  return (
  - <LocalizationProvider dateAdapter={DateFnsUtils}>
  + <LocalizationProvider dateAdapter={DateFnsAdapter}>
  <DatePicker value={selectedDate} onChange={date => handleDateChange(date)} />
  <TimePicker value={selectedDate} onChange={date => handleDateChange(date)} />
  <DateTimePicker value={selectedDate} onChange={date => handleDateChange(date)} />
  