docs: Add usage information and coverage report to docs

[kevintyj]

What is the purpose of this PR?

Add usage information and coverage report to docs. This will help users better utilize the action.

ClickUp/Jira/Github project ticket number(s)?

What did you do?

Add Vitest coverage report to CI pipeline Reach 100% coverage Add codecov to CI & repository Fix ignore patterns for test reports

How do we test it?

Vitest test suites all passing

Checklist before merging

• [x] Added tests where necessary
• [x] Performed a self-review of my code
• [x] Ensure all acceptance criteria are met
• [x] Implemented the UI as exactly as the design (applicable only for UI changes)
• [x] Added comments for codes where hard-to-understand
• [x] Haven't pushed unnecessary files (ex: .env, .map)
• [x] Haven't ignored Typescript warnings in the code (if do so add a comment with the reason)

Provide screenshot details of the PR

[optional] Tests passed screenshot

[optional] Breaking changes after PR

Anything else?

[codecov[bot]]

Welcome to Codecov :tada:

Once merged to your default branch, Codecov will compare your coverage reports and display the results in this comment.

Thanks for integrating Codecov - We've got you covered :open_umbrella: