docs(demo): pump example version

Author: mohatt

example/package.json

@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "gatsby": "^2.13.51",
-    "gatsby-plugin-advanced-pages": "^1.1.0",
+    "gatsby-plugin-advanced-pages": "^1.2.0",
     "gatsby-source-filesystem": "^2.1.8",
     "gatsby-transformer-remark": "^2.6.10",
     "react": "^16.8.6",