Add flake8-docstrings

[dalonsoa]

Description

Adds flake8-docstrings plugin to check the docstrings in the code while running the linter.

Fixes #36

Type of change

• New feature (non-breaking change which adds functionality)
• Optimization (back-end change that speeds up the code)
• Bug fix (non-breaking change which fixes an issue)

Key checklist

• Make sure you've run the pre-commit checks: $ pre-commit run -a
• All tests pass: $ poetry run pytest

Further checks

N/A

• Code is commented, particularly in hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[LivDaniel]

I'm not sure I have enough knowledge to be a competent reviewer on this. My only thought was did David say we should exclude Fiona for now or did we decide to keep it in?

[davidorme]

I think we should also add this to pre-commit as well:

  - repo: https://gitlab.com/pycqa/flake8
    rev: 3.9.2
    hooks:
      - id: flake8
        additional_dependencies: [flake8-docstrings]

[dalonsoa]

Done!

[davidorme]

Ack. Should have expected that the docstrings would fail. I did some fixing in the PR for #51 - not sure if I hit all of them.

[dalonsoa]

I'll try to sort this out on Monday

[davidorme]

It's failing on my messy docstrings 😞 I've merged in from develop and cleaned up the remaining ones.