Per https://www.python-httpx.org/compatibility/#proxy-keys, there should
always be a `://` after the protocol. The given examples raise an
exception when used as-is.
Co-authored-by: Florimond Manca <florimond.manca@protonmail.com>
Co-authored-by: Tom Christie <tom@tomchristie.com>
* Drop nox in favor of vanilla scripts
* Use named stages
* Fix attrs dependency resolution madness
* Add missing mkautodoc dev dependency
* Add missing install step on windows build
* Explicitly define stage order so that timed out Windows build runs last
* Add missing dev dependency on Black
* Clean up contributing guide
* Separate docs into docs-build and docs-serve
