message: adding link to dev npm build
diff: @@ -15,6 +15,7 @@ Tone.js is a Web Audio framework for creating interactive music in the browser.
  * download [full](https://tonejs.github.io/build/Tone.js) | [min](https://tonejs.github.io/build/Tone.min.js)
  * `npm install tone`
  +* dev -> `npm install tone@next`
  [Full Installation Instruction](https://github.com/Tonejs/Tone.js/wiki/Installation).
  