feat: require that users link their discord to apply to certain vacancies

Signed-off-by: miguel456 <me@nogueira.codes>

app/Exceptions/DiscordAccountRequiredException.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace App\Exceptions;
+
+use Exception;
+
+class DiscordAccountRequiredException extends Exception
+{
+}