Enhancements to histogram generation and sequential folder processing

[bobleesj]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update

Description (Screenshots, files, etc)

1. Bin Width in Legend: Histograms now include the bin width (distribution range) in the legend, providing clearer insights into the data distribution.
2. Consistent X-Axis for Histograms: Both site and element histograms now have consistent x-axes, making them easier to compare.
3. Individual Histograms Saving: Histograms can now be saved individually in a 2x1.5 inch format, organized in a specified folder.

Data Processing Enhancements

1. Excel Sheet Summary: The Excel output now includes average and standard deviation at the end of the sheet, offering a quick statistical overview.

User Experience Improvements

1. Folder Processing Options: The tool now processes all folders by default, with an option for users to select specific folders if needed.
2. Customizable Histograms via JSON: Users can now customize histograms using a JSON configuration, produced via the python plot-histogram.py command. This feature allows for interactive customization of the bin width.

Checklist

• Are the tests passing?
• If it's a new feature, have tests been written?
• Is the code linted using Black?
• Have you performed a self-review of your code?

Added to documentation?

• README.md
• No documentation needed