add tone example

packages/tone/README.md

@@ -8,6 +8,33 @@ This package adds Tone.js functions to strudel Patterns.
 npm i @strudel.cycles/tone --save
 ```
 
+## Example
+
+The following example will create a pattern and play it back with tone.js:
+
+```js
+import { sequence, stack, State, TimeSpan } from '@strudel.cycles/core';
+import { Tone, polysynth, osc, out } from '@strudel.cycles/tone';
+
+const pattern = sequence('c3', ['eb3', stack('g3', 'bb3')]).tone(polysynth().set(osc('sawtooth4')).chain(out()));
+
+document.getElementById('play').addEventListener('click', async () => {
+  await Tone.start();
+  Tone.getTransport().stop();
+  const events = pattern.query(new State(new TimeSpan(0, 4))).filter((e) => e.whole.begin.equals(e.part.begin));
+  events.forEach((event) =>
+    Tone.getTransport().schedule((time) => event.context.onTrigger(time, event), event.whole.begin.valueOf()),
+  );
+  Tone.getTransport().start('+0.1');
+});
+```
+
+[open in codesandbox](https://codesandbox.io/s/strudel-tone-example-5ph2te?file=/src/index.js:0-708)
+
+## API
+
+See "Tone API" in the [Strudel Tutorial](https://strudel.tidalcycles.org/tutorial/)
+
 ## Dev Notes
 
 - `@tonejs/piano` has peer dependency on `webmidi@^2.5.1`! A newer version of webmidi will break.