Lazy-load components

[jelbourn]

1. First step will be to only load the docs-site specific components as necessary (e.g., example-viewer)
2. Follow-up will be to load only the material components and examples that are used in the current view. This part will be tricky because all of the individual component pages are loaded through example-viewer.

[Splaktar]

PR #698 starts down the path of lazy loading our documentation components and demonstrates some of the issues with the current implementation of ComponentViewer, DocViewer, and ExampleViewer.