Add demos

[Tony20221]

The first thing I want to do when I go to some UI controls is I want to see what they look like before I read walls of text or look at code.
Where are the demos of the controls?

[3kh0]

I think v2 is here: https://material-components.github.io/material-web/demos/index.html

v3 is still in the works

[abhijeet-shelhalkar]

Material Web Components Playground: https://mwc-demos.glitch.me/

[KTibow]

also see https://lit.dev/playground/#gist=3704ea8df1a2f252be6012db2c5403df

[maischus]

I found this overview of working components:
https://olkus.com/projects/using-web-components-with-material-3/

[asyncLiz]

Demos are available at our WIP catalog material-web.dev