Adapt long description
* Documentation: https://docs.gammapy.org
* Code: https://github.com/gammapy/gammapy
-Gammapy is an open-source Python package for gamma-ray astronomy built on Numpy and Astropy.
-It has been adopted by Cherenkov Telescope Array Observatory as the CTA Science Analysis Tools,
+Gammapy is an open-source Python package for gamma-ray astronomy built on Numpy, Scipy and Astropy.
+It is the base library for the science analysis tools of the Cherenkov Telescope Array Observatory
and can also be used to analyse data from existing gamma-ray telescopes.
