add facebook link

content/_index.de.md

@@ -38,6 +38,7 @@ Die Sprechstunden finden im Blauen Haus (Christoph-Probst-Straße 12) Zimmer 028
 
 ## Kontakt
 * <i class="fa fa-comments" aria-hidden="true"></i> [Impressum](/impressum)
+* <i class="fa fa-facebook-official" aria-hidden="true"></i> [SSN bei Facebook](https://www.facebook.com/stustanet/)
 * <i class="fa fa-github" aria-hidden="true"></i> [SSN bei Github](https://github.com/stustanet/)
 
 

content/_index.en.md

@@ -38,6 +38,7 @@ The office hours take place in Blue Building (Christoph-Probst-Straße 12) Room
 
 ## Contact
 * <i class="fa fa-comments" aria-hidden="true"></i> [Imprint](/impressum)
+* <i class="fa fa-facebook-official" aria-hidden="true"></i> [SSN on Facebook](https://www.facebook.com/stustanet/)
 * <i class="fa fa-github" aria-hidden="true"></i> [SSN on Github](https://github.com/stustanet/)
 
 {{% /column %}}{{% /two-columns %}}