Add [docformatter](https://github.com/PyCQA/docformatter) for Python
docstrings.
By default it outputs diffs but changes in-place with `--in-place`. On
successful change it exits with an error code of `3` (found out by
trial), so I had to add a formatter wrapping-script.
Initially I used `--in-place` with the special `in-place` symbol in
apheleia. But now I tried an approach where I transform the diff into
usable stdout using `patch` instead.
Related to #266 , where I had used the example of docformatter to ask
how to add scripts with positive exit codes and @raxod502 showed me the
`phpcs` solution.
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Co-authored-by: Radon Rosborough <radon@intuitiveexplanations.com>
