create a demo using blockly

[hcientist]

FYI Chris Johnson @twodee built something that helped me conceive of this project idea. https://deltaphone.twodee.org/ I just think that we do bi-direction version, and that likely for us it starts in the other direction (person makes notes on scale and gets blocks)

[LukeHennessy501]

After starter code from Stewart:

• Deal with toggling duration --> deltaphone
• Rest block (also has duration)