renamed compressible folder and added compressible Euler solver

cfs-solver/cfs-Euler-01/cfs-eulerSolver.ipynb

cfs-solver/cfs-Euler-01/mesh_close.png

cfs-solver/cfs-Euler-01/mesh_full.png

cfs-solver/cfs-Euler-01/naca.xml

cfs-solver/cfs-Euler-01/result_full_P4.png

cfs-solver/cfs-Euler-01/session_naca-Complete.xml

cfs-solver/cfs-Euler-01/session_naca.xml

cfs-solver/cfs-Euler-01/session_naca_NS-Complete.xml

cfs-solver/cfs-Euler-01/session_naca_ex-Complete.xml

cfs-solver/cfs-Euler-01/session_naca_ex.xml

cfs-solver/cfs-Euler-01/session_naca_im-Complete.xml

cfs-solver/cfs-Euler-01/session_naca_im.xml

cfs-solver/cfs-NS-01/cns-basicExplicit.ipynb

cfs-solver/cfs-NS-01/cyl2D.xml

cfs-solver/cfs-NS-01/image/cyl2D_sketch.jpg

cfs-solver/cfs-NS-01/session.xml