Link from /submit-vote for AirGappedVoter to add auth info

pages/api/submit-vote.ts

@@ -39,7 +39,11 @@ export default async (req: NextApiRequest, res: NextApiResponse) => {
       electionDoc.update({ num_pending_votes: firestore.FieldValue.increment(1) }),
     ])
 
-    return res.status(200).json({ link_auth, message: 'Submission received' })
+    return res.status(200).json({
+      link_auth,
+      message: 'Submission received',
+      visit_to_add_auth: `https://siv.org/election/${election_id}/auth?link=${link_auth}`,
+    })
   }
 
   // 1. Validate auth token