[About] update contact email

Author: jpthiele

content/_index.md

@@ -17,7 +17,7 @@ The GAMM RSE & RDM chairs are  (interim at least until the kick-off workshop):
 - Dr. Robert Speck (Forschungszentrum Jülich)
 - Dr. Jan Philipp Thiele (TU Braunschweig)
 
-{{< button href="mailto:[email protected]" >}}
+{{< button href="mailto:[email protected]" >}}
 {{<icon "envelope">}} Contact the Chairs
 {{</ button >}}