Documentation edits to README.md

[willingc]

Proposed edits to increase user readability and ease of use of the README page.

[pfalcon]

Thanks for fixing typos and inserting articles. I'm less sure about other changes, because they sometimes go up to slightly changing the meaning ;-). As an example, I'm sure there should not be quotes around "highly experimental", so I'm going to revert them. But otherwise, it's hard for a non-native speaker to argue with the native one, so if you say it makes it easier to read, let's go with it.

[willingc]

@pfalcon Thanks. Happy to help. For future reference, I'm cool with making any edits to PRs that I submit :) Cool project.