work on documentation

corsika/framework/process/BaseProcess.hpp

corsika/framework/process/ContinuousProcess.hpp

corsika/framework/process/DecayProcess.hpp

corsika/framework/process/InteractionProcess.hpp

corsika/framework/process/NullModel.hpp

corsika/framework/process/ProcessReturn.hpp

corsika/framework/process/ProcessSequence.hpp

corsika/framework/process/ProcessTraits.hpp

corsika/framework/process/SecondariesProcess.hpp

corsika/framework/process/StackProcess.hpp

corsika/framework/process/SwitchProcessSequence.hpp