Gammaalps

This release includes a number of pull requests that improve memory handling, a new magnetic field model, and improved numerical precision:

- The numerical prefactors entering the momentum difference terms (the Delta terms) are now derived using their definitions from physical constants using the `astropy.units` and `astropy.constants` modules (PR 27 )
- A new magnetic field environment has been added, which describes a structured magnetic field in a galaxy cluster (PR 28 29 30 ) as used in [Libanov & Troitsky (2020)](https://ui.adsabs.harvard.edu/abs/2020PhLB..80235252L/abstract). This is also included in a new [tutorial notebook](https://gammaalps.readthedocs.io/en/latest/tutorials/mixing_ICM_structured_field.html).
- Memory handling has been improved, in particular, the transfer matrices are not stored in memory any longer (PR 31)
- Spline support has been added for the photon-photon dispersion in AGN jets (PR 32, 33), as described in [Davies et al. (2022)](https://ui.adsabs.harvard.edu/abs/2022PhRvD.105b3017D/abstract)

This release features several new features and important bug fixes:

- The notebooks in the tutorials now come with syntax highlighting (PR 8), and several bugs / typos in the tutorials where fixed (issues 21, 24 )
- In the helical / tangled jet environment (`JetHelicalTangled`) it is now possible that the photons are emitted at arbitrary positions (PR 10)
- Additional dispersion terms `chi` can now be provided as 2D `scipy.interpolate.RectBivariateSpline` objects and the redshift dependence has been added for mixing in the IGMF (PR 13 18 )
- The behavior of the logging has been improved by adding a custom logger for (PR 14)
- The EBL environment is now handled like any other environment as a proper transfer matrix (PR 15)
- Fixed bugs in the computation of the Gaussian turbulent field (20)
- Fixed bug in how final transfer matrix was computed (issue 19, PR 22)

This version fixes a couple of minor bugs and updates the doc strings. It also now supports installation on windows machines.

This is an initial release of the gammaALPs code.