* First pass at autodoc support
* Add mkautodoc requirement for docs builds
* Linting
* pip install httpx when building docs, to make it available to mkautodoc
* Fix code example in docstring slightly
* Use latest mkautodoc to resolve rendering of code snippets in docstrings
* Fill in 'Helper functions' API docs
* First pass at documenting Client
* Add autodoc for Client
* Update to mkautodoc 0.1
* Fix typos
