feat: Added a Rock, Paper Scissors

[nxora]

Description (summary)
This PR adds a new Rock–Paper–Scissors command-line game implemented in C. The implementation follows the same structure and style as the existing Hangman template (clean comments, game_instance struct, modular functions). Features include:

Player vs Computer gameplay

Configurable number of rounds

“Play again?” loop to restart without exiting

ASCII art for Rock / Paper / Scissors

Clear, minimal code comments and readable control flow

Simple input validation and score tracking

Motivation / Why

Provides a second example program using the same template style as hangman for consistency and learning.

Useful for teaching program structure, random seeding, and simple game loops.

Adds a lightweight demo project that can be compiled and run without dependencies.

Files added / modified

rps/rps.c — new file: full Rock–Paper–Scissors implementation (main, new_game, play_round, picture, etc.)

(optional) rps/README.md — short usage instructions (if you want me to add this I can include it)

No changes to existing hangman files.

Behavioral changes / Compatibility

No breaking changes to existing code. New program is isolated under rps/.

Build tools unaffected; to compile manually: gcc -o rps rps/rps.c or add to existing Makefile if desired.

How to test / QA steps

Compile: gcc -o rps rps/rps.c

Run: ./rps

Enter number of rounds (e.g., 3) when prompted.

For each round, enter 0 (Rock), 1 (Paper) or 2 (Scissors).

Observe ASCII art, per-round results, and final match result.

When match finishes, respond y/n when prompted with Play again? to verify the loop restarts and resets scores.

Try invalid inputs (e.g., 5, -1, letters) and confirm input validation prompts again.

Note: current implementation checks numeric range; non-numeric input behavior depends on terminal—if you want robust handling for non-numeric input we can add a fgets() + strtol() wrapper.

How many rounds do you want to play? 3

---- Round 1 ----
Choose your move:
[0] Rock
[1] Paper
[2] Scissors
Enter choice: 0

You chose: Rock
Computer chose: Scissors

Your move:
    _______
---'   ____)
      (_____)
      (_____)
      (____)
---.__(___)

Computer move:
    _______
---'   ____)____
          ______)
       __________)

🟢 You win this round!
Score → You: 1 | Computer: 0

Play again? (y/n):

Implementation notes / decisions

RNG seeded per new_game() with srand(time(NULL)) so each match varies.

Input is validated for numeric range (0–2). If you prefer full string-based validation (to safely handle non-numeric input), I can replace scanf("%d", &player) with fgets() + strtol() parsing.

ASCII art taken from common rock-paper-scissors examples and printed for both player and computer.

Follow-ups / possible improvements (future PRs)

Add Makefile entry for building rps and integration into existing build/test pipeline.

Add README.md in rps/ with usage, compile instructions, and sample output.

Add "best-of-N" convenience helper (auto-calculate rounds required to win).

Improve input robustness: accept rock/paper/scissors text, or keyboard shortcuts.

Add unit tests around any parsing/helper functions (if refactored to be testable).

Related issues / tickets

Closes: #1533