feat: Add frontend-design plugin to marketplace

Add a new plugin that helps create distinctive, production-grade frontend interfaces with high design quality. The plugin includes a skill that generates creative, polished code avoiding generic AI aesthetics.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude-plugin/marketplace.json

@@ -90,6 +90,17 @@
       },
       "source": "./plugins/learning-output-style",
       "category": "learning"
+    },
+    {
+      "name": "frontend-design",
+      "description": "Create distinctive, production-grade frontend interfaces with high design quality. Generates creative, polished code that avoids generic AI aesthetics.",
+      "version": "1.0.0",
+      "author": {
+        "name": "Prithvi Rajasekaran & Alexander Bricken",
+        "email": "prithvi@anthropic.com"
+      },
+      "source": "./plugins/frontend-design",
+      "category": "development"
     }
   ]
 }