docs: use twoslash-eslint instead of playground (#936)

Related to
#824 (comment)

Author: ota-meshi

docs-svelte-kit/build-system/build.ts

@@ -16,6 +16,8 @@
     "@babel/types": "^7.25.8",
     "@fontsource/fira-mono": "^5.1.0",
     "@ota-meshi/eslint-plugin": "^0.17.5",
+    "@shikijs/markdown-it": "^1.24.0",
+    "@shikijs/twoslash": "^1.24.0",
     "@sindresorhus/slugify": "^2.2.1",
     "@sveltejs/adapter-static": "^3.0.5",
     "@sveltejs/kit": "^2.7.2",
@@ -56,9 +58,9 @@
     "stylus": "^0.64.0",
     "svelte": "^5.0.3",
     "svelte-adapter-ghpages": "0.2.2",
+    "twoslash-eslint": "^0.2.12",
     "util": "^0.12.5",
     "vite": "^6.0.0",
-    "vite-plugin-eslint4b": "^0.5.0",
     "vite-plugin-svelte-md": "^0.1.7"
   }
 }