message: Customize colors in muiTheme for material dev page
diff: +import { green, purple } from '@mui/material/colors';
  import { createTheme, ThemeProvider } from '@mui/material/styles';
  import * as React from 'react';
  import { createRoot } from 'react-dom/client';
  import { App } from 'react-querybuilder/dev';
  import { materialControlElements } from '../src';
  -const muiTheme = createTheme();
  +const muiTheme = createTheme({
  + palette: {
  + primary: {
  + main: purple[500],
  + },
  + secondary: {
  + main: green[500],
  + },
  + },
  +});
  createRoot(document.getElementById('app')!).render(
  <React.StrictMode>
  