Publish live demo and skills.sh install links

[rob163]

Summary

• Link the README preview and demo CTA to the GitHub Pages live demo instead of the GitHub HTML source view.
• Add skills.sh and license badges.
• Remove private-repo and local-clone install notes from the public install section.
• Add docs/index.html as a GitHub Pages redirect to the demo page.

Deployment

• GitHub Pages is enabled from main:/docs.
• Live demo verified: https://rob163.github.io/html-as-cli-panel-skill/demo/cli-panel.html
• Repository homepage set to the live demo URL.
• skills.sh badge returns 200; the detail page/search are still not indexed yet after a real public npx skills add install, so this may require skills.sh background indexing.

Validation

• npm run validate
• npx skills add rob163/html-as-cli-panel-skill --list
• curl -I -L https://rob163.github.io/html-as-cli-panel-skill/demo/cli-panel.html