reset.scss leaks EP-specific styles to the rest of the pattern library

When building out the Eleventy Patterns scaffolding I wanted some basic reset styles:

```
* {
box-sizing: border-box;
margin: 0;
padding: 0;
}
```

I added these in `reset.scss` but since they target `*` the styles can end up affecting pattern examples. We'll need to rethink our approach here so that styles written for the scaffolding don't impact the end user's patterns

(Either that or we decide some resets are necessary and put up a disclaimer about it)