Add redirect for /api (graphql#4327)

This is popular on google as an index page

Author: JoviDeCroock

website/vercel.json

@@ -0,0 +1,9 @@
+{
+  "redirects": [
+    {
+      "source": "/api",
+      "destination": "/api-v16/graphql",
+      "permanent": true
+    }
+  ]
+}