Fix spelling

Author: richelbilderbeek

docs/day3/matplotlib/README.md

@@ -23,4 +23,4 @@ COSMOS     |`module load matplotlib/3.8.2` (avoid version `3.9.2`!)
 Dardel     |`module load PDC/23.12 cray-python/3.11.5 matplotlib/3.8.2-cpeGNU-23.12`
 Kebnekaise |`module load matplotlib/3.8.2`
 Pelle      |`module load matplotlib/3.9.2-gfbf-2024a`
-Tetralth   |`module load buildtool-easybuild/4.8.0-hpce082752a2 GCC/13.2.0 Python/3.11.5 SciPy-bundle/2023.11 matplotlib/3.8.2`
+Tetralith  |`module load buildtool-easybuild/4.8.0-hpce082752a2 GCC/13.2.0 Python/3.11.5 SciPy-bundle/2023.11 matplotlib/3.8.2`