Document code styling and linting if required

[manics]

Is your feature request related to a problem? Please describe.

There's evidence in a commit message of the black autoformatter being used in the past: https://github.com/executablebooks/github-activity/commit/e8df68f923d04ff5ae87e18e1a366c0f9f92b3af but it doesn't look like it's mandatory at the moment, it's not enforced in CI and there's no pre-commit or other configuration file.

The executable books contributing guidelines say

Coding style is largely enforced automatically, using pre-commit hooks. For Python packages, the pre-commit should include automated code formatting via Black and code linting via flake8.

Describe the solution you'd like

Guidance on code formatting and linting, or a statement that it's not required

Describe alternatives you've considered

N/A

Additional context

[welcome[bot]]

Thanks for opening your first issue here! Engagement like this is essential for open source projects! :hugs:
If you haven't done so already, check out EBP's Code of Conduct. Also, please try to follow the issue template as it helps other community members to contribute more effectively.
If your issue is a feature request, others may react to it, to raise its prominence (see Feature Voting).
Welcome to the EBP community! :tada: