-Merged all new changes from main into the fitting module rutine.
-New rutine on observables downloads filter.dat files if they don't exist locally and stores them.
-Future pull request will add the different tutorials (Illustris, Salim, synthetic photometry)
-Merged all new changes from main into the fitting module rutine. -New rutine on observables downloads filter.dat files if they don't exist locally and stores them. -Future pull request will add the different tutorials (Illustris, Salim, synthetic photometry)