button-toggle alignment and material.angular.io issues

[fxck]

1. combination of text and icon is not aligned well

2. styles in overview on material.angular.io are broken, or not working
   

[julianobrasil]

The styles ara a little bit strange in sidenav too at material.io.

Also the sidenav is not working there (already reported in #4944).

[jelbourn]

@tinayuangao the icon alignment is a minor issue; the example styles are more important

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