Add missing instructor names for upcoming R workshop

Adds the names of the instructors to the page of the "Programming with R" workshop on 22./23. November 20212.

_events/2021/11/2021-11-22_R.md

@@ -4,7 +4,10 @@ layout: event
 organizers:
   - meessen
 lecturers:
-  - TBA
+  - Annajiat Alim Rasel
+  - Marco de Lucia
+  - Ranjeet Singh
+  - Richard Gayle
 type:   workshop
 start:
     date:   "2021-11-22"