Add audio playback in examples/realtime

[64bit]

Currently examples/realtime only prints text, make it play the audio received via ServerEvent.

[dynamite-bud]

Hey, I started to work on this issue and I've made an example.

Currently, I am able to save the audio to a file which can be played using ffmpeg.

Should I play the output received from OpenAI using system's speaker or should an example saving the audio suffice ?