Dev requirements

• The format and license header of codes must be well checked before merge to main branch. We have use a Github Action to ensure this rule.
• It is recommended to use pre-commit hook or run ./scripts/format.sh && ./scripts/add-license.sh manually before daily submitting.
• All important classes and methods(e.g. abstract method) of newly submitted codes must have complete comments. The reviewer can refuse to pass the PR until sufficient comments are added.