Tutorial 7: Monoid, Functor, Applicative, and Monad - init (#13)

* Init from MarekSuchanek/FPCourse

* Improved outline, refs and hw info

* Brief intro to category theory

* Renumbering file and hw

* revisions

* Monoid and Semigroup done

* Functor: Lifting and Math

* Functors done

* Applicative done + start Monad

* Monad and IO done

* Grammar check & fix

* revisions

* Changed do-notation a bit

* Improved fmap comment for CT functor

Author: MarekSuchanek