Include text output in full screen mode/while sharing

Currently, while viewing the sketch in full screen/while sharing the accessible text output is not present.
**Possible solutions :**
Include a textOutput parameter while viewing the sketch in fullscreen
http://alpha.editor.p5js.org/full/<sketch_id>?textOutput=1
And then in the share window, update the UI so there's a button to add the query string parameter to the URL.
