update CHANGELOG.md

Author: ufechner7

CHANGELOG.md

@@ -11,6 +11,7 @@
 - add the packages `JLD2` and `Colors` to the system image
 #### Added
 - add examples `calc_spectrum.jl` and `plot_spectrum` to plot the eigenfrequencies of the system
+- the script `calculate_rotational_inertia.jl` for calculating the inertia matrix of the kite
 - function `menu2()` which displays a menu with scripts for model verification
 
 ### KiteModels v0.6.11 2024-11-09