Add liquid-skills plugin (#1507)

.claude-plugin/marketplace.json

@@ -824,6 +824,22 @@
       "source": "./external_plugins/linear",
       "homepage": "https://github.com/anthropics/claude-plugins-public/tree/main/external_plugins/linear"
     },
+    {
+      "name": "liquid-skills",
+      "description": "Liquid language fundamentals, CSS/JS/HTML coding standards, and WCAG accessibility patterns for Shopify themes",
+      "author": {
+        "name": "Shopify"
+      },
+      "category": "development",
+      "source": {
+        "source": "git-subdir",
+        "url": "https://github.com/Shopify/liquid-skills.git",
+        "path": "plugins/liquid-skills",
+        "ref": "main",
+        "sha": "ae3e4cc3f454923e388bbd841fd931f0c7bf5be4"
+      },
+      "homepage": "https://github.com/Shopify/liquid-skills/tree/main/plugins/liquid-skills"
+    },
     {
       "name": "lua-lsp",
       "description": "Lua language server for code intelligence",