Introduce an asynchronous generator function `play_audio_async` in `src/rspeech/play.py` that initializes the pygame mixer, loads and plays a given audio file, then yields control every 100ms while the music is still busy, enabling non-blocking audio playback in async contexts.
Append a "Need help?" section to the project README, including a contact email address (retoor@molodetz.nl) and a note about the project's limited development timeframe.
