GitLab

* Use mdformat pre-commit hook

* allows consecutive numbering

* improve .mdformat.toml

* test mdformat

* format markdown

* minor fix

* fix codespecll

* fix circleci

* add linkify-it-py dependency for cicleci

* add comments

* replace flake8 url

* add mdformat-myst dependency

* remove mdformat-myst dependency

* update contributing.md