Complete notes for the 1D shock tube problem

[yungyuc]

Complete the notes for the analytical solution of the one-dimensional shock tube problem.

[yungyuc]

@Gene0315, could you please review the issue and let me know if you can follow the writing? After the review, I'd like to ask for your help to add notes for #31.

[Gene0315]

@yungyuc, I think I can follow the writing. Adding the notes for #31 is also ok.

[yungyuc]

Thanks, @Gene0315 , let me assign this issue to you. I'd like to ask for your help to check if the shock tube analytical solution is indeed complete.