Update AUTHORS.md

Author: tehrengruber

AUTHORS.md

@@ -9,7 +9,7 @@
 - Deconinck, Florian. SSAI/NASA-GSFC
 - Ehrengruber, Till. ETH Zurich - CSCS
 - Elbert, Oliver D. NOAA-GFDL
-- Faghih-Naini, Sara - ECMWF
+- Faghih-Naini, Sara. ECMWF
 - Farabullini, Nicoletta. ETH Zurich - C2SM
 - George, Rhea. Allen Institute for AI
 - González Paredes, Enrique. ETH Zurich - CSCS