Astrometry-net-client

Added a new upload command: anc_upload

Updated the documentation & added the `URLUpload` class.

What's Changed
* Update documentation related to Settings by StenSipma in https://github.com/StenSipma/astrometry_net_client/pull/43
* Bump requests from 2.28.1 to 2.31.0 by dependabot in https://github.com/StenSipma/astrometry_net_client/pull/41
* New version of concurrent upload by StenSipma in https://github.com/StenSipma/astrometry_net_client/pull/45


**Full Changelog**: https://github.com/StenSipma/astrometry_net_client/compare/v0.2.10...v0.3.0

Make package available for Python 3.11.

Mainly dependency upgrades to solve security vulnerabilities.