enable CI/CD via github actions

[williballenthin]

add the following checking:

• [x] #44
• [x] #43
• [x] black code formatting #55
• [ ] flake8 code checking
• [ ] ruff code checking
• [ ] mypy type checking

configure GH action to do the check. also register the check via pre-commit as described below.

fyi @sldouglas-nist @ajnelson-nist