message: examples - fix url for Tone.Offline
diff: <tone-explanation label="Offline Rendering">
  Tone.Offline renders a chunk of Tone.js code into an AudioBuffer. An offline instance of Tone.Transport is passed into the callback which can be used to schedule events. It may take a moment to render the sound.
  <br><br>
  - <a href="https://tonejs.github.io/docs/Tone#offline">Tone.Offline</a> docs.
  + <a href="https://tonejs.github.io/docs/Tone#offline-static">Tone.Offline</a> docs.
  </tone-explanation>
  <tone-content>
  