Extend and Validate (4)

What's Changed

• Add vendor extension support to Content.Encoding type by @ayushshrivastv (#405)
• Added a Validation that checks all operationIds in Link objects are valid by @ayushshrivastv (#404)

New Contributors

• @ayushshrivastv made their first contribution in #405

Full Changelog: 4.0.0-rc.2...4.0.0-rc.3