chore: add skills.opper.ai to README links

Also triggers the first Verify (this PR) and Deploy (on merge) runs —
the merge that introduced the workflow files didn't trigger them, which
is standard GitHub Actions behavior for the first push of new workflows.

Author: Jose-Sabater

README.md

@@ -159,6 +159,7 @@ MIT
 
 ## Links
 
+- [Skills index (live)](https://skills.opper.ai)
 - [Documentation](https://docs.opper.ai)
 - [Platform](https://platform.opper.ai)
 - [Cookbook](https://github.com/opper-ai/opper-cookbook)