Update docs to be explicit for odd setups

[bzmw]

I have a bit of an odd setup and I had to do define the following in my requirejs.conf

    'react': 'bower_components/react/react-with-addons',
    'JSXTransformer': 'bower_components/react/JSXTransformer',
    'jsx': 'bower_components/requirejs-react-jsx/jsx',
    'text': 'bower_components/requirejs-text/text'

the text module is required my requirejs-react-jsx and with an odd setup it doesn't find it magically.

[alexwasner]

I had a similar issue that was resolved with @bzmwillemsen fix

[srn]

Thanks guys, I've added the text plugin in the readme.md.