[FR] Add CI/CD for Testing, Formatting, and Markdown Spell Checking

[DiFronzo]

Is your feature request related to a problem? Please describe.
I'm always frustrated when code changes break tests, introduce formatting issues, or when spelling mistakes slip into Markdown documentation because there is no automated way to catch these problems before merging.

Describe 1~3 use cases of the purposed feature

• As a developer, I want all code to be automatically tested and formatted on every push or pull request, so I can be confident my changes don't break anything or introduce style issues.
• As a maintainer, I want Markdown files to be checked for spelling errors automatically, so documentation remains professional and easy to read.
• As a contributor, I want to receive clear feedback from CI/CD if my code or documentation needs fixes, so I can address issues quickly.

Describe alternatives you've considered

• Manually running tests, formatters, and spell checkers before each commit or PR, but this is error-prone and easy to forget.
• Relying on code reviews to catch these issues, but this increases reviewer workload and can let mistakes slip through.

Additional context
This feature would use GitHub Actions (or a similar CI/CD system) to run pytest for tests, flake8 or black for formatting, and a tool like mypy for Markdown spell checking. All checks would run on every push and pull request, and the pipeline would fail if any issues are