add warning on AAI cert rollover

index.md

@@ -6,6 +6,9 @@ additional_css:
     - frontpage.css
     - title/service-title-buttons.css
 additional_js: frontpage.js
+notification:
+  title: "Helmholtz AAI certificate renewal"
+  description: "Today (Friday Sept 16) there will be a certificate renewal on Helmholtz AAI (central login). Thus, the connection to your organisation might be interrupted and login failing. If you need to use connected services, please login beforehand at https://login.helmholtz.de between 11:00 and 11:30 and keep the session running."
 excerpt:
   "HIFIS aims to provide excellent, seamlessly accessible IT services for the
   whole Helmholtz Association."