## New in 1.0
* Breaking change: all instances now need to specify the variance of all type
parameters.
* Breaking change: instances of the form `NFunctor (f a)` are no longer
allowed. Instead, write `NFunctor f` and use `NonvariantT` to indicate that
`a` cannot be mapped.
* `NFunctor` is now even more general: in addition to generalizing `Functor`,
`Bifunctor`, `Trifunctor`, etc., it now also generalizes `Contravariant`,
`Invariant`, and `Profunctor`!
* Introducing new infix operators corresponding to each variance. `(<#>)` is
still used for covariant type parameters, so after updating the instances,
all the call sites which were using the 0.1 API should still work. `(>#<)` is
used for contravariant type parameters, `(<#>/>#<)` is used for invariant
type parameters, which can be mapped given both a covariant and a
contravariant function, and `(ðŸ‘»#ðŸ‘»)` is used for phantom type parameters.
* Introducing the `(-#-)` operator, which can be used instead of any other
operator in order to leave the corresponding type parameter untouched.
* Introducing support for mapping over type parameters of kind `* -> *` using
natural transformations. The corresponding infix operators have two hashes:
the covariant operator is `(<##>)`, the contravariant operator is `(>##<)`,
etc.
* Introducing the `VarianceTransformer` typeclass, via which you can add
support for other variances and other kinds.
* It is no longer needed (nor allowed) to write both an `NFunctor Either`
instance and an `NFunctor (Either a)` instance corresponding to `Either`'s
`Bifunctor` and `Functor` instances. Instead, the `NFunctor (Either a)`
instance is derived from the `NFunctor Either` instance.
## New in 0.1.0.0
* Initial release of the `NFunctor` typeclass