Update mario_ppo.zip with new 25M model file and add .gitignore for macOS files

Update mario_ppo.zip: replace model file with updated 20M model

Update README.md: add 25M steps checkpoint and adjust training timesteps

Update README.md: add environment details and training timesteps information

Update README.md: correct model path and increase timesteps to 20 million

Upload mario_ppo.zip with huggingface_hub

Upload mario_ppo.zip with huggingface_hub

Upload mario_ppo.zip with huggingface_hub

Create README.md

initial commit