[sound]: documentation: `play_wave`

```
import { play_wave } from "sound";
const pi = math_PI;
play_wave(t => math_sin(2 * pi * t * 440), true); // true should be 1
```
gives confusing error message:
```
Line 3: Error: play is expecting sound, but encountered t => t >= duration ? 0 : wave(t),true
```