Add check workflow

[EthanThatOneKid]

Add a GitHub workflow that checks proposed PRs for formatting, linting, and test errors.

Prior art

• https://github.com/acmcsufoss/form/blob/581e2cea7ed0b0b873c61b05cb5a9c4d9606f99b/.github/workflows/check.yaml
• https://github.com/acmcsufoss/shorter/blob/a36345efac6697202257dfb8c5e32460a9986b6b/.github/workflows/check.yaml
• https://github.com/acmcsufoss/boardd/blob/15cc024733fd853c6494dbf5c7c5a17afcea42f4/.github/workflows/check.yaml
• https://github.com/acmcsufoss/perks/blob/f01960bc2f9c16186bd3f3cc41d3b08f4354ba0b/.github/workflows/check.yaml
• https://github.com/acmcsufoss/codemod/blob/51bf4530ad07911c6b1296734c56e8cb84a2005d/.github/workflows/check.yaml
• https://github.com/acmcsufoss/tldr/blob/ae68b005516a1af948b9d228b91d2a35b371dbf2/.github/workflows/check.yml