README.md: markdown fixes

Hi,
The readme seemed to have some broken formatting as seen rendered on Github, so I thought I could send you some small fixes.

Also, by the way, would it be possible that you could provide a usage example for some simple two-file "helloworld.c"-like project? I'd be very grateful, as for now I'm having trouble understanding how (and actually whether at all) the app can be used for such a case?

Thanks,
/Mateusz.