Setup cron in install/freshrss-install.sh (#2412)

json/freshrss.json

@@ -34,6 +34,10 @@
     {
       "text": "Database credentials: `cat ~/freshrss.creds`",
       "type": "info"
+    },
+    {
+      "text": "Per FreshRSS documentation, a cron job to actualize FreshRSS will be setup at `/etc/cron.d/freshrss-actualize`. This can be adjusted as needed",
+      "type": "info"
     }
   ]
 }