docs: add error and schema management guides

Author: sarahxsanders

website/pages/docs/_meta.ts

@@ -42,6 +42,8 @@ const meta = {
     title: 'FAQ',
   },
   'going-to-production': '',
+  'production-errors-debug': '',
+  'production-schema-management': '',
   'scaling-graphql': '',
 };