Add codespell CI workflow (expected to fail)

[szepeviktor]

From #20

[TomasVotruba]

Typos give great opportunity to first-time contributors :) I want to keep it that way, so this won't be added.

[szepeviktor]

I need to be much smarter to persuade you 🙃

[TomasVotruba]

Aim for lazy, simple and needed 😉