Fixed slightly confusing typo

Former-commit-id: 6ecc3b176515c287f25cbf49a1791e20fe04e71b

README.md

@@ -60,7 +60,7 @@ KADMOS is currently being developed at [TU Delft](https://tudelft.nl) by [Imco v
 Changelog
 =========
 
-## 0.9.11 (10/12/2020)
+## 0.9.11 (10/12/2021)
 
 - Inclusion of partitioning algorithms in uncoverged-MDA/OPT/DOE and converged-DOE architectures
 - Several small bug fixes and code cleanup