gha: add `codespell` with `pre-commit`

[jbampton]

Add custom dictionary codespell.txt

We are only checking the docs folders

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

https://pre-commit.com/

[jbampton]

More hooks can be added in future

"Git hook scripts are useful for identifying simple issues before submission to code review. We run our hooks on every commit to automatically point out issues in code such as missing semicolons, trailing whitespace, and debug statements. By pointing these issues out before code review, this allows a code reviewer to focus on the architecture of a change while not wasting time with trivial style nitpicks."