Make OpenCV prototype shareable

[brettfiedler]

We want to be able to share the OpenCV marker prototype, but we do not intend to spend much time with rigorous documentation or bug testing. We also accept that it will not be screen reader accessible to set up or change the settings.

Right now, it lives here:
https://phet-dev.colorado.edu/html/jg-tests/opencv-test/

We want to

• Update the sim inside the iframe with the published sim
• Move the prototype out of jg-tests and to somewhere where we can comfortably share it out via direct links or on the newly revamped Prototypes page

This does not block Quad publication and should only be done during downtime (code review/testing) or after publication!

JG EDIT: Link to relevant issue with code and documentation prototype (It was never checked in): #20

[brettfiedler]

Will assign myself and reassign to dev when we think there might be time here.