Calendar.md

@@ -12,6 +12,7 @@ Here is a tentative calendar for the lectures at ULiège:
 | 21/03     | 💻 group work with instructors                                 |
 | 28/03     | 💻 group work with instructors                                 |
 | **29/03** | 📓 **Progress report #2 - Scalar DG solvers**                  |
+| 31/03     | 🏭 Company visit in Charleroi (Cenaero)                        |
 | *04/04*   | ⛱️ *NO CLASS ("PAQUES")*                                       |
 | *11/04*   | ⛱️ *NO CLASS ("PAQUES")*                                       |
 | 18/04     | 💻 group work with instructors                                 |