Improve code spell check

[FabijanC]

Usage related changes

• None

Development related changes

• Improve after feat: add codespell workflow for CI #443
• Spelling check (installation and execution) is now a script in scripts/ which is used in .circleci/config.yml and can be used locally (e.g. in pre-commit)
• Add .git/hooks/pre-commit notice to README.md

Checklist:

• Checked the relevant parts of development docs
• Applied formatting - ./scripts/format.sh
• No linter errors - ./scripts/clippy_check.sh
• No unused dependencies - ./scripts/check_unused_deps.sh
• Performed code self-review
• Rebased to the latest commit of the target branch (or merged it into my branch)
• Updated the docs if needed, including the TODO section
• Linked the issues which this PR resolves
• Updated the tests if needed; all passing (execution info)

[xiaolou86]

wonderful improvement 👍