add support for reading doc8 config from pyproject.toml file

[swaldhoer]

This pull request

• adds support for reading a doc8 configuration from a pyproject.toml file and
• removes deprecated function readfp by read_file

Details:

• Reading from ini-files has not been changed, except for removing the deprecated function call to a non-deprecated one
• The pyproject.toml file is only taken into account if the toml package is available.
• If a configuration file is passed as argument and the path is not a file, it is ignored and warning is printed. No other configuration files are taken into account, therefore the default configuratoin is used.

[swaldhoer]

This Pull Request is WIP, as the pyproject configurations is not parsed into the exact same object as from the ini file.

[ssbarnea]

This will also need some testing. Also it would a good idea to covert to draft if is not ready for reviews.

[swaldhoer]

This will also need some testing. Also it would a good idea to covert to draft if is not ready for reviews.

I will add tests, that make sure that the configuration dict ist the same for the current configuation files and pyproject.toml

[swaldhoer]

erm why did this get merged? This implementation is not complaint with the current implemtation of how the *.doc8 is parsed.

In my opinion the way how *.doc8 is parsed is bad and it should be parsed the way it is done in this merge request. But this would be a breaking change. So this is something that needs to be discussed.