embed examples as webcomponent in the documenation

[spike-rabbit]

Our current approach of using iframes has a significant negative performance impact.
It typically fails when more than 3/4 examples are embedded in a single page.
Yet, in many cases we would need more.

• ensure root-font !== 16px work (web-components cannot have a root font-size)
• mkdocs theme must use correct font (the latest variable font ideally)
• live-preview needs support rendering as web component
  - [ ] cdk overlay must be customized
  - [ ] router needs to mocked for examples