- Remove unnecessary deserialization page
- Fix typos
- Rearrange quickstart guide

instead of a function that returns instances of the serializer

Also fix usage of Meta.fields with dumps method

Expose them publicly through the serialize and deserialize methods

Show type of underlying exception

Also add Serializer#make_object method for creating an object with
the deserialized data

Also implement Email field deserialization

Also implement Enum field deserialization

- Concrete classes define _serialize and _deserialize.
- Remove @validated decorator. Validation...

DateTime implementation is incomplete (doesn't handle timezones)
Also add test stubs

Move required validation to avoid custom validation messages overriding required message

This feels like a better place to do the required validation, and allows
for custom error messag...

[fixes #24]

validated() was previously wrapped on both output() and format() methods, but
not consistently, ...

because subclasses may need to override the data property

Adds a registry of serializer classes
[see #19]

[fixes #20]

[should fix #21]

This will make it possible for 3rd-party libraries to extend the fields
module