fix(deps): update dependency nuxt to v2.18.0

Author: renovate[bot]

package.json

@@ -13,7 +13,7 @@
   },
   "dependencies": {
     "@nuxt/content": "2.4.3",
-    "nuxt": "2.16.2"
+    "nuxt": "2.18.0"
   },
   "devDependencies": {
     "@nuxtjs/color-mode": "3.2.0",