Add external plugin modern-web-guidance (#2533)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

.github/plugin/marketplace.json

@@ -828,6 +828,28 @@
         "sha": "b4ffffc810130893117a7b8f797e0a33102e66de"
       }
     },
+    {
+      "name": "modern-web-guidance",
+      "description": "Modern Web Guidance is an agent skill and CLI tool designed to help AI coding agents build web applications using modern, secure, and high-performance APIs rather than outdated workarounds.\nSupported by the Google Chrome team, it injects expert-curated web platform best practices directly into an agent's context window to prevent the generation of bloated, legacy code.",
+      "version": "0.0.179",
+      "author": {
+        "name": "GoogleChrome",
+        "url": "https://github.com/GoogleChrome"
+      },
+      "repository": "https://github.com/GoogleChrome/modern-web-guidance",
+      "homepage": "https://developer.chrome.com/docs/modern-web-guidance",
+      "license": "Apache-2.0",
+      "keywords": [
+        "frontend",
+        "web",
+        "baseline"
+      ],
+      "source": {
+        "source": "github",
+        "repo": "GoogleChrome/modern-web-guidance",
+        "ref": "v0.0.179"
+      }
+    },
     {
       "name": "modernize-dotnet",
       "description": "AI-powered .NET modernization and upgrade assistant. Helps upgrade .NET Framework and .NET applications to the latest versions of .NET.",