docs: update README.md to include available methods for `miniflux.Cli…

…ent`

Miniflux Python API Client 1.1.3

* feat!: drop support for Python 3.7
* ci: use Ruff for linting and formatting
* feat: allow to pass a requests.Session object to the Miniflux client
* docs: convert README.rst to Markdown

ci: use trusted publishing

ci: add older Python versions to test matrix

fix: type hints should be backward compatible with old Python versions

feat: add `get_enclosure()` and `update_enclosure()`

Add more specific exceptions

Release version 1.0.0

Add custom user agent

Convert setup.py to pyproject.toml

Bump version