A horizontal 'header bar' for use between the navigation menu and the main content on any page. Has 
pre-defined sizes our designers like.

```javascript
<div style={{ padding: '30px' }}>
    <H1>The navigation menu is here</H1>
    <HeaderBar>
      <Label>Header bar content with some link</Label>
      <Anchor>You messaging URI</Anchor>
    </HeaderBar>
</div>
```
