Give code template for users to fill in

My thoughts are like providing a notebook, with some code templates targeting at different user scenarios. Including different session kind / loading various graph / run algorithms & get output / traversal / learning template.

For Kubernetes deploy, The notebook can be located in the jupyter container we integrated in helm charts.

This may overlap with our tutorial notebooks in function, I'm open to further discussions to see if this is necessary or other adjustment.

Update: Gives link to docs/tutorials in the jupyter notebook templates. Proposed in #1124