Fix typo in pages data docs example (#136)

Author: brettle

src/pages/docs/content-as-data/pages-data.md

@@ -89,7 +89,7 @@ We would get this additional content as data out:
       },
       {
         "content": "First Point",
-        "slug": "first-post"
+        "slug": "first-point"
       }
     ]
   }