Add consistent folder naming convention for project directories

Description

Project folders and script files in this repository use inconsistent naming formats — some use spaces (Banking App), others underscores (snake_game), and others are all caps (SNAKE).
This inconsistency makes navigation harder and lowers the repository’s overall readability.

Steps to Reproduce

1. Browse the root directory of the repository.
2. Compare folder names like Banking App, SNAKE, and WeatherApp.
3. Notice the different naming styles (spaces, underscores, uppercase, etc.).

Expected Behavior

All project directories and files should follow a single, consistent naming convention, such as:

• all lowercase
• words separated by underscores (banking_app, snake_game)

Actual Behavior

Names are inconsistent; some use spaces or uppercase, causing confusion and irregular sorting.

Suggestion

• Decide one convention (e.g., lowercase_with_underscores).
• Rename existing folders accordingly.
• Add a short note in the README or CONTRIBUTING.md describing the convention.

Environment

• Repository branch: main
• Observed: 13th November, 2025

Start by inventorying the root directories and script files, including examples such as Banking App, SNAKE, and WeatherApp. Review README.md and CONTRIBUTING.md to see where the naming rule should be documented, then define the final convention before renaming items and checking for references that still use the old names.