Add audio

[leleosilva]

The crates rodio or cpal could possibly be used for the audio.

Creating an 'beep' sound with rodio is easy, but a new instance of source is needed everytime the audio is played.

Ex. code for 'beep' in rodio:

use std::time::Duration;
use rodio::{OutputStream, Sink};
use rodio::source::{SineWave, Source};

fn main() {

    let (_stream, stream_handle) = OutputStream::try_default().unwrap();
    let sink = Sink::try_new(&stream_handle).unwrap();

    // Add a dummy source of the sake of the example.
    let source = SineWave::new(440.0).take_duration(Duration::from_secs_f32(0.25)).amplify(0.20);
    sink.append(source);

    // The sound plays in a separate thread. This call will block the current thread until the sink
    // has finished playing all its queued sounds.
    sink.sleep_until_end();
    
}

Things to note:

• Does rodio (or cpal) affect the timing of the CPU cycle?
• Does rodio or cpal have WASM support?