Demo cases using jupyter notebook

[kyoungseoun-chung]

We need to create jupyternotebook for demo cases.

[kyoungseoun-chung]

List to be added:

• [x] Poisson pure dirichlet
• [ ] Poisson pure Neumann
• [ ] Poisson mixed
• [ ] Poisson periodic
• [ ] Advection-diffusion
• [ ] Navier-stokes
• [ ] Fokker-planck
• [ ] Black-scholes