Add pre-commit action to run interrogate

[tchklovski]

I looked into it a bit and recommend adding the following config. in particular,
pass_filenames: false
is needed for some reason, as per econchick/interrogate#60

  - repo: https://github.com/econchick/interrogate
    # cf http://www.pydocstyle.org/en/stable/index.html
    rev: 1.4.0
    hooks:
      - id: interrogate
        args: [ -vv, --config=pyproject.toml ]
        # see https://github.com/econchick/interrogate/issues/60
        pass_filenames: false

[tchklovski]

other documentation checkers:

• https://github.com/terrencepreilly/darglint
• http://www.pydocstyle.org/en/stable/index.html
  I think we're fine with the basics though