Initialising repository
Adding signing componenet
Adding make infrastructure
Adding to/from textual serialisers
Tweaking availability zone parser
Adding preliminary V4 signing adaptation from previous amazonka
Ensuring consistency of licensing and updating module heirarchy
Correcting namespace
Removing unused expansions
Adding dependencies
Restructuring serialisation related functions into distinct namespace

Preference is for having everything serialisation related colocated
under one branch of the namespace, prefixed by the top-level library namespace.

This is more 'future proof' in regards to potentially using another
libraries' namespace.
Adding basic error handling specifics and applying to metadata retrieval
Re-formatting region documentation
Replacing MonadError with EitherT
Re-enabling auth retrieval timer
Documentation wording
Newline
Adding constructors and lenses for various request formats/styles
Correcting module exports
Correcting namespace