Change summary and description

I really don't want to call things the ___ Monad.

Haskell people (including me) always say things like, "To print things out you need to use the IO monad." This is like saying, "To add numbers you need to use the Addition Monoid". It's just really weird to describe the algebraic properties of the thing in it's name. It also focuses on characteristics you don't need to fully appreciate to be able to use and understand the library.

In both these cases, we made something simple sound magical and complex. I want Elm people to say "To print things out, use the IO library" and to make it parallel "To add numbers, use addition."