Update README.md

README.md

-# Informatik Vorbereitungskurs 2020
+# Informatik Vorbereitungskurs 2021
 
 ## Links
 
 * iLearn: https://ilearn.th-deg.de/course/view.php?id=9755
-* Teams: https://teams.microsoft.com/l/meetup-join/19%3ameeting_Y2E1OWQzYzYtNWFmMy00YTcyLWIxNGEtNjBmOWJiYmY2YjE5%40thread.v2/0?context=%7b%22Tid%22%3a%220da197c5-f6fb-490d-af72-f398d01b6c29%22%2c%22Oid%22%3a%22b0160232-8c54-405d-a14f-d53068afb53d%22%7d
-* BigBlueButton: https://bbb.th-deg.de/b/and-498-zha
+* Teams: https://teams.microsoft.com/l/meetup-join/19%3ameeting_ZDc1ZDcxNjMtNzJlYy00ODNkLTg2YTEtMzMwOTM0NWI2MDc1%40thread.v2/0?context=%7b%22Tid%22%3a%220da197c5-f6fb-490d-af72-f398d01b6c29%22%2c%22Oid%22%3a%22b0160232-8c54-405d-a14f-d53068afb53d%22%7d
 
 ## Dozent
 Prof. Andreas Fischer (andreas.fischer@th-deg.de)