Provided dedicated notebooks for cuml.accel

[csadorf]

We should provide dedicated notebooks to document and demonstrate the use of cuML.accel as part of our notebooks/ collection.
Notebooks that are specific to cuML.accel should be easily identifiable e.g., via a common prefix or a dedicated directory.

Here are some suggestions on notebooks we should add:

• Quickstart - Installation, basic sklearn/UMAP examples, performance comparison
• Runtime Comparisons - Between CPU, cuML, and cuML.accel
• Real-world Applications - Genomics, financial, image data processing
• Profiling, Troubleshooting & Best Practices - How to profile the code, optimize memory management, troubleshoot common issues

[Zo-arch]

Hello, I would like to work on this issue. I will start with the 'Quickstart' notebook.