Previously, when documenting links, it was necessary to provide the
link extractor that should be used to get the links from the response.
This commit improves on this by adding support for determining the
link extractor to use based on the response's content type. Two
content types are currently supported; application/hal+json and
application/json. For other content types, an extractor can be
provided as before when calling withLinks.
Closes#7
cae7e3fb58