Multiple render format constructors

[Lazerbeak12345]

Is your feature request related to a problem? Please describe.
The library only supports browsers right now.

Describe the solution you'd like
Add constructors for:

• StringRenderer
• Ctd2dRenderer (current)
• [ ] WebGL render targets #68
• MultiRenderer to pipe render output to more than one other renderer

Take a renderer (as seen above) as the first and only argument to PIxelManipulator. The renderer will tell PixelManipulator the canvas sizes.

• [ ] Restore the zoom elm to a semblance of its former glory. (commit 7a8cf0d disgraced it)
  • [ ] On-update event #69
  • [ ] Tidy up demo code to be readable for a complete newb to the library #70

Describe alternatives you've considered

Additional context
The addElement function will need significant rework to define what color (or string, etc.) each element is using. The data would be passed to the renderer when an element is modified or added.

Relies on changes made in #53

• Separate renderers to different file if possible.

[Lazerbeak12345]

in a3356af I added a SplitRenderer that is like MultiRenderer but it only supports two renderers.

[Lazerbeak12345]

According to the typescript documentation, that's the only way to do it.

[Lazerbeak12345]

Just made a .dot file of the current structure of this app.

[Lazerbeak12345]

Working on a way to modularize. At a glance, it doesn't seem to be doable without extreme restructuring - and even then the zoomelm is too tightly bound to the Pixelmanipulator Instance

[Lazerbeak12345]

It seems that most of the modularization issues around the zoom element involve the current absence of an onupdate function.

It's worth looking into the whole event system to see where it can be improoved.