Organize Notebooks into Category-Specific Folders

[ahnaf-tahmid-chowdhury]

Description

Currently, all notebooks in this repository are placed in the root folder. The examples in the OpenMC documentation are organized into specific categories, such as Model Building, Reactor Examples, Other Examples, Tallies and Visualization, Nuclear Data, Features, Multigroup Cross Section Generation, Multigroup Mode, and Unstructured Mesh. It would be beneficial to mirror this structure in the repository by placing notebooks into corresponding folders.

Proposed Change

• Create folders for each category as listed in the OpenMC documentation:
• Move the relevant notebooks into these category-specific folders.
• Update any paths or references within the notebooks to ensure functionality remains intact after the reorganization.

Benefits

• Improves the navigability and user experience of the repository by allowing users to quickly find notebooks relevant to their needs.
• Aligns the repository structure with the OpenMC documentation, making it easier for users to reference examples.
• Simplifies cloning and integrating the repository with environments like NukeLab without requiring modifications.