Move all code into one cmake project

_code/.gitignore

_code/CMakeLists.txt

_code/cmake/shared_settings.cmake

_code/notes/real_ode_solutions.py

_code/pset_02/pset_02_math.py

_code/pset_02/pset_02_plots.py

_code/pset_03/CMakeLists.txt

_code/pset_03/rand/CMakeLists.txt

_code/pset_03/rand/main1.cpp

_code/pset_03/rand/main2.cpp

_code/pset_03/rand/xorshift.h

_code/pset_03/scripts/pset_03_diagrams.py

_code/pset_03/scripts/pset_03_lfsr.py

_code/pset_03/scripts/pset_03_math.py

_code/pset_03/scripts/pset_03_rand1.py

_code/pset_03/scripts/pset_03_rand2.py

_code/pset_03_rand/.gitignore

_code/pset_04/CMakeLists.txt

_code/pset_04/cmake/shared_settings.cmake