Fix typos in README

There's another under the [Config files section](https://github.com/remy/nodemon/blob/master/README.md#config-files). Relevant passage in bold:

> The above nodemon.json file might be my global config so that I have support for ruby files and processing files, and I can simply run nodemon demo.pde and nodemon will automatically know how to run the script **even though out of the box support for processing scripts.**

I wasn't sure what this was trying to say exactly so I left it alone.