* Installs Sass

* installs concurrently

* Ports CSS to SCSS

* Gitignores CSS build output

* Moves public/main.css to scss/index.scss

* Fixes port to SCSS

* Use-ifies base styles

* Use-ifies layout styles

* Use-ifies modules styles

* Use-ifies variables

* Use-ifies utils

* Moves normalize to scss

* Implements a CSS minifying step with CSSO

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Co-authored-by: Joe Carstairs <jcarstairs@scottlogic.com>