feat(lint): add support for GitHub Actions output format

[rjelierse]

What/Why/How?

Add a new output format for the lint subcommand that can be used in a GitHub Actions workflow directly.

Reference

Testing

Screenshots (optional)

Check yourself

• [x] Code changed? - Tested with redoc/reference-docs/workflows (internal)
• [x] All new/updated code is covered with tests
• [x] New package installed? - Tested in different environments (browser/node)

Security

• [ ] Security impact of change has been considered
• [ ] Code follows company security practices and guidelines

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: db066f2eb643dcdf227311b173292c425db0f54c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

| Name | Type | | --------------------- | ----- | | @redocly/openapi-core | Minor | | @redocly/cli | Minor |

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[tatomyr]

@rjelierse I wonder why you've changed the package-lock file. Is that intentional?

[rjelierse]

@rjelierse I wonder why you've changed the package-lock file. Is that intentional?

It's a leftover from testing with local version of @redocly/openapi-core, I will undo the change to package-lock.json