Fix typo and missing description of content in folder (#2004)

Fixes #2001 .

### Description
These fixes are suggested by Cursor + claude-4-sonnet, with a prompt:

```
Please review the documentation (markdown/jupyter) in the tutorial repo  for clarity, with a focus of typo fixes and language refinement
```

### Checks
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Avoid including large-size files in the PR.
- [x] Clean up long text outputs from code cells in the notebook.
- [x] For security purposes, please check the contents and remove any
sensitive info such as user names and private key.
- [x] Ensure (1) hyperlinks and markdown anchors are working (2) use
relative paths for tutorial repo files (3) put figure and graphs in the
`./figure` folder
- [x] Notebook runs automatically `./runner.sh -t <path to .ipynb file>`

Signed-off-by: Mingxin Zheng <mingxinz@nvidia.com>