[docs] Update the docs about server rendering

[Stupidism]

Problem Description

server-rendering is not the lastest nor most useful. It's something like this:

import getMuiTheme from 'material-ui/lib/styles/getMuiTheme';
import themeDecorator from 'material-ui/lib/styles/theme-decorator';

const muiTheme = getMuiTheme({userAgent: req.headers['user-agent']});

class Main extends React.Component {
  render() {
    return (
      <div>Hello world</div>
    );
  }
}

export default themeDecorator(muiTheme)(Main)

Origin

I met a server-render problem caused by auto-prefixer in react-starter-kit. I noticed a req variable is needed for this server-render solution, so I found this entrance. But renderToString just cant render themeDecorator(muiTheme)(component).

Solution

Finally, I found this code in your example

<MuiThemeProvider muiTheme={muiTheme}>
  {someComponent}
</MuiThemeProvider>

and solved the problem.

const muiTheme = getMuiTheme({userAgent: req.headers['user-agent']});
const resultComponent = React.createElement(MuiThemeProvider, {muiTheme}, component);

Suggestion

Normally, when I have a req variable, I have only a component but not the Main class.
So, for others' good, I suggest you guys add an optional solution in doc for server-rendering when class is not available, which will be

import getMuiTheme from 'material-ui/lib/styles/getMuiTheme';
import MuiThemeProvider from 'material-ui/lib/MuiThemeProvider';

const muiTheme = getMuiTheme({userAgent: req.headers['user-agent']});
const resultComponent = React.createElement(MuiThemeProvider, {muiTheme}, component);

[mikehuebner]

Having a similar issue, is the wrapper the only thing that fixes said problem?