Add material for Geant4 exercise

Geant4.pdf

Geant4_Part1.ipynb

Geant4_Part2.ipynb

HadronicShower.png

geant4_simulation/__init__.py

geant4_simulation/actions.py

geant4_simulation/geometry/__init__.py

geant4_simulation/geometry/compcalor.py

geant4_simulation/geometry/example_geometry.py

geant4_simulation/geometry/febox_with_tailcatch.py

geant4_simulation/geometry/pbbox.py

geant4_simulation/geometry/samplingcalo.py

geant4_simulation/geometry/tumortherapy.py

geant4_simulation/libphyslist.so

geant4_simulation/materials.py

geant4_simulation/physicsList/CMakeLists.txt

geant4_simulation/physicsList/src/EMPhysics.cc

geant4_simulation/physicsList/src/EMPhysics.hh

geant4_simulation/physicsList/src/MyQGSP_BERT.cc

geant4_simulation/physicsList/src/MyQGSP_BERT.hh