Sidebar theming

The appearence of the sidebar can be customised by specifing a theme in the config JSON used to build auspice. This theme is then available (via styled-components) to the components rendered in the sidebar. It is also passed to the nav bar component as the theme prop.

This interface is very experimental and will change frequently. Perhaps we'll use https://refactoringui.com/previews/building-your-color-palette/ as a guide to both naming and the number of properties available here.

{
  "sidebarTheme": {
    "background": "#F2F2F2",
    "color": "#000",
    "sidebarBoxShadow": "rgba(0, 0, 0, 0.2)",
    "font-family": "Lato, Helvetica Neue, Helvetica, sans-serif",
    "selectedColor": "#5097BA",
    "unselectedColor": "#333"
  }
}