Grammar issues fixed in README

[ZebruhX]

Fixed some minor grammar issues in README including article usage, noun determiners, and commas.

[SpenceKonde]

Thankyou.

Uh, I don't suppose you could submit this against branch 2.0.0-dev? Nothing in this branch is being carried over to the next release.

[SpenceKonde]

I think I've now fixed it to use v2.0.0-dev as the default