Add codespell support (config, workflow to detect/not fix) and make it fix few typos

[yarikoptic]

More about codespell: https://github.com/codespell-project/codespell .

I personally introduced it to dozens if not hundreds of projects already and so far only positive feedback.

CI workflow has 'permissions' set only to 'read' so also should be safe.

[Nusnus]

Thanks!