[FEATURE] Add automated spell-checking to docs repo

[cpengilly]

add automated spell-checking to docs repo via plugin or AI

problem: lots of small typos, grammatical mistakes and spelling errors across docs. we need to automate fixing these smaller errors somehow

solution: improves docs and overall professionalism; reduces # of small PRs coming thru with one spelling error, so we can have collective and wider, amazing OP community focus on larger content changes :)

[cpengilly]

we can consider grammatical checks later but it'll be harder to implement