Add Architecture Docs

[IPWright83]

Add MDX for:

• VirtualCanvas
• canvasRenderLoop / progressiveCanvasRenderLoop (INTERNAL)
• renderElements (INTERNAL)
• renderVirtualCanvas/renderVirtualElements (INTERNAL)
• withSVG (INTERNAL)
• withCanvas (INTERNAL)
• withStore (INTERNAL)
• withXYPlot (INTERNAL)