Sans

- Improved typehinting
- URL helpers now return `httpx.URL` rather than `httpx.Request`
- exponential backoff implemented
- private shards now available with `NSAuth`
- `Response.iter_xml` and `Response.aiter_xml` will unpack gzip responses automatically i.e. data dumps
- README.rst now has some examples
- Docs are building again, but aren't written yet
- Minorly improved performance of various `Response.*xml` methods
- Fixed `utils.prepare_and_execute` to find the correct token XML element
- Used cpython's implementation of `ElementTree.indent` for backport

Fix some erroneous typehints in client.pyi

Complete rewrite using httpx and core xml.

Bumps dependencies and removes upper bound on python version

* Increments API and Python version

* Fixes raise_for_status being suppressed
* Requests will no longer raise if iteration is stopped
* Api.last_response will now store last_response information even if the response was an error.