docs: remove `docs` in preparation for `git subtree add`
Squashed 'docs/' content from commit 89439cc

git-subtree-dir: docs
git-subtree-split: 89439ccd8fa645318c62584f320a4dbae10e80e0
Merge commit '59247098ae6fc907c50ecdbf71a8fe5fe4c8c98c' as 'docs'
docs: fixed extractor typo in `docs/build/index.hmtl`