Container Tutorial for PI 2.0

The tutorial is divided into two parts:

1. Basic : Basic of Singularity for PI 2.0
2. Advance : Usage of U2CB (Unprivileged User Container Build Solution)

Reference:

1. https://sylabs.io/guides/3.6/user-guide/index.html
2. https://docs.hpc.sjtu.edu.cn/job/container/singularity/
3. https://docs.hpc.sjtu.edu.cn/job/container/u2cb/