Attempt to make things a bit clearer

Added two lines to try to make clear that cupcake is more than just the chrome extension. The second line makes it seem like that is all that the project is. With this line I believe the roadmap becomes a bit more clear.

Apologies if I continue to misunderstand.
Merge pull request #5 from cholmes/patch-1

Attempt to make things a bit clearer [readme]