Integrate QEDprocesses.jl

[szabo137]

The subpackage QEDprocesses.jl needs to be integrated into QED.jl. This includes the following tasks:

• make the top-level namespace of QEDprocesses.jl available in QED.jl
• add docs of QEDprocesses.jl as a page to the docs of QED.jl
• add integration tests from QEDprocesses.jl into the test suite of QED.jl
• pin the version of QEDprocesses.jl used in the current version of QED.jl

Requirements

The following items are required for QEDprocesses.jl to be integrated into QED.jl:

• implementation of a static process type defining the scattering process, e.g. Compton, Breit-Wheeler and trident
• implementation of the necessary type parameters for the process type, including model types for perturbative and pulsed-perturbative QED
• implementation of a data structure to hold and propagate the kinematical information about the initial particles of a given process
• implementation of differential and total cross-sections as well as the maximum of the differential cross-section for all included processes
• unit tests to check the exposed functions for correctness (this will be called by QED.jl test suite)
• integration tests for any dependency within QED.jl (this will be called by QED.jl test suite)

The docs of QEDprocesses.jl should at least contain

• a landing page in the QEDprocesses.jl docs describing the purpose of the package
• API reference for all exposed functions and data types, as well as the respective page in the docs of QEDprocesses.jl
• a quickstart section showing the main functionality