feat(skills): Add icon-finder skill

[bekah-stephens]

Summary

This skill closes the loop on icon discovery by allowing your AI agent to search the @rhds/icons ui set (~542 icons) by described use case. It interprets natural-language prompts like "find me an icon for cloud deployment," derives search terms, fetches the live icon list from the Red Hat Icons demo site, and returns matched icons in both a markdown table and a visual HTML preview styled with PatternFly 6. Each card in the preview displays outline and fill variants side-by-side with individually clickable links to the source SVGs on GitHub, along with software-UI-specific context hints to help users evaluate which icon best fits their use case. If the initial results aren't sufficient, a deep search fallback expands to synonyms, related concepts, and domain-specific terminology to surface icons the user may not have thought to search for.

• Adds new icon-finder skill with SKILL.md containing the full search workflow (use case interpretation, demo site fetch, keyword matching, fill variant detection, HTML preview generation, and deep search expansion)
• Includes PatternFly 6 CDN-based HTML preview template with responsive gallery layout, clickable icon variant links, and "UI context:" hints per card
• Includes footer linking to a custom icon request form for cases where no existing icon fits
• Includes .gitignore to exclude generated icon-finder-preview.html preview artifacts
• Works in both Cursor and Claude Code with no dependencies beyond a browser

Test plan

• Verify SKILL.md renders correctly in a markdown viewer
• Confirm skill triggers on expected user prompts (e.g. "find an icon", "search for an icon", "pick an icon for", "icon options for")
• Run a search (e.g. "find an icon for cloud") and verify the HTML preview opens with PatternFly-styled cards, correct outline/fill variant links, and "UI context:" hints
• Verify cards link to the correct SVGs on GitHub (/blob/main/src/ui/ for browsing, /raw/.../src/ui/ for rendering)
• Trigger a deep search and confirm expanded results appear in a separate section below the originals with no duplicates
• Verify the custom icon request link in the footer opens the correct Google Form