quick update of index.md to May

Author: sunito

index.md

@@ -2,9 +2,9 @@
 
 ## Upcoming events
 
-Our meetup this month will be on a **Monday**, February **17th** at 7 pm. Same place as the last months, at [WIAS](https://www.wias-berlin.de/). 
+Our next meetup will be on **May 20th** at 7 pm. As usual, at [WIAS](https://www.wias-berlin.de/). 
 
-Again, it will be on the **4th floor**. \
+Perhaps, the construction work will be finished by then, otherwise it will be on the **4th floor** again. \
 At the entrance, there is a registration book for guests. Enter Dr. Fuhrmann as the person to be visited.
 
 ## Regular meeting