Improve documentation consistency and remove obsolete CheerpJ implementation

[Copilot]

Addressed missing Javadoc coverage and inconsistent documentation across shell scripts to improve codebase accessibility for new contributors.

Changes

Java Documentation

• Added class-level Javadoc to NumberGuessingGame explaining console game loop and error recovery
• Documented ScannerHelper.next() for input stream clearing after exceptions
• Documented CheckGuess.quit() for play-again validation

Shell Script Documentation

• Added purpose, output, and usage comments to all packaging and testing scripts
• Clarified differences between platform-specific packaging approaches (macOS JRE structure differs from Linux/Windows)
• Explained build dependencies in test scripts (.bat requires manual build, .sh auto-builds)

Cleanup

• Removed obsolete CheerpJ implementation (replaced by TeaVM in previous work)
  • Deleted cheerpj.sh and cheerpj/ directory
  • Updated teavm.sh comments to reflect replacement

Example of improved documentation style:

/**
 * Console-based Number Guessing Game implementation. This class manages the console version of the
 * game, handling the game loop, user interaction, and error recovery. It prompts the user to guess
 * numbers and allows replaying the game.
 */
public class NumberGuessingGame {
    /**
     * Runs the console version of the Number Guessing Game. Initializes all game components,
     * displays debug information, and manages the game loop. The user can play multiple rounds
     * until they choose to quit.
     */
    void run() {

Original prompt

Make sure everything is documented, in a consostant style, easy for newbies to read, amd clean up the unneeded things

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