Review this package in light of gammapy recent developments

[HealthyPear]

Since the original script was developed, gammapy evolved quite a bit.

At some point we should review the entire package to see if we can substitute some features with gammapy and/or integrate some more advanced features.

[HealthyPear]

This would basically entail to not use the current scripts, but the gammapy API top use the IRF of the instrument which the user wants to use for the proposal and run an estimation of the flux / sky map

• 1D example https://docs.gammapy.org/1.2/tutorials/analysis-1d/spectrum_simulation.html
• 3D case example https://docs.gammapy.org/1.2/tutorials/analysis-3d/simulate_3d.html