Use Box/Grid component in examples

[mikemurray]

Update examples to use the Box components in examples instead of divs/components with style properties. This is to showcase some of the more generic components the Box and Grid components in many different use cases.

import { Box } from "@material-ui/core"
https://material-ui.com/system/basics/#all-inclusive

import { Grid } from "@material-ui/core"
https://material-ui.com/components/grid/#grid