Lego-certbot

This is a major release that brings `lego-certbot` out of beta, and publishes it as a package on PyPI.

Added

* Add Python 3.11 as a supported version

Changed

* Change version to `1.0.0` to signify `lego-certbot` coming out of beta
* Instead of doing version-specific behaviour, add the backport `importlib-metadata` as a dependency and always use the new API
* Fix Certbot `DNSAuthenticator` type hints
* Require at least Python 3.8.1 (for `flake8 6.0.0`)
* Set more relaxed `poetry-core` install dependency restrictions
* Update the development utilities (`black`, `isort`, `flake8`, `mypy`) to their latest versions
* Add Python package metadata to Poetry configuration
* Update the documentation to improve wording, and change installation instructions to download from PyPI

Removed

* Remove the `metaname` extra package set (these should always be installed by the user)

* Replace `pre-commit.ci` with GitHub Actions, as the former does not allow Internet access and automatic dependency updates are not required

* Don't hard-code the `_acme-challenge` subdomain
* Explicitly pass the root domain for the ACME challenge as `LEGOCERTBOT_DOMAIN` instead of inferring it from the `TXT` record name
* Add `--version` parameter
* Fix `poetry-core` version pin so that `pip install` will work
* Fix inconsistencies and typos in comments and `README.md`
* Add Tips and Tricks related to Lego v4.9.0's CNAME traversal change in `README.md`

Initial release