Tidied wording, some sentence structure, & typos.

There have been some complaints by Erlangers on Twitter about the typos and sentence structure of this README, so I thought I'd help out a bit :-)

Hopefully this reads more smoothly and is more approachable to the skeptic, while still carrying the original enthusiasm :-)
Merge pull request #4 from oubiwann/master

Tidied wording, some sentence structure, & typos.