Update README.md

update for formatting; what problem this solves; how it is solved content addition
Use Markdown URL syntax for clickable links

I'm sure there's a good reason that they weren't clickable (accessibility? other-flavor of MD?) but figured if I was gonna ask about it, might as well PR too.
Merge pull request #1 from virtualandy/master

Make links clickable in the readme
Merge pull request #1 from project-open-data/master

Doc improvements