Migrate `aws/gpu_tree_shap/gpu_tree_shap.ipynb` to deployment docs

[jacobtomlinson]

Migrate aws/gpu_tree_shap/gpu_tree_shap.ipynb to deployment docs.

See #203 (comment) for detailed migration instructions.

### Tasks
- [ ] Decide if notebook should be migrated and add "migrate: X" label (if no also close this issue)
- [ ] Test if notebook works
- [ ] Fix up anything that needs changing
- [ ] Ensure notebook has good title, description and metadata tags in the first cell
- [ ] Replace deployment instructions with links to docs pages
- [ ] Copy notebook into a new folder into deployment docs examples
- [ ] Copy any supporting files to the folder
- [ ] Add notebook to examples toctree
- [ ] Make PR to deployment docs repo