Demonstrate overriding styles

[glenrobson]

We have very basic styles (layout) we need to override these by targeting the attribute.

We should also document how this is done. Cite other projects that do it this way (radix).

[glenrobson]

Step 1: tidy up the existing styles.
Step 2: dependant on #20 and #21

[glenrobson]

Demo worked on in the meeting:

https://codesandbox.io/s/stupefied-wu-j018dr?file=/src/App.js

Ed is going to style it so it looks more like the UV thumbnail panel and then show a demonstration of overriding.

[glenrobson]

Looking into the default styles using: https://github.com/sindresorhus/modern-normalize