docs: Update list of officially supported browsers (#3082)
docs: Update list of officially supported browsers (#3082)

- Remove "Opera". We don't test in it, and it uses the same rendering engine as Chrome (Blink)
- Reorganize list into a map of browsers to OSes (I find it easier to read)
material-components/material-components-web,material-components/material-components-web,material-components/material-components-web