Improves the UI atomization and the relative documentation (#13)

* ITCSS structure refactoring

* Improves logo versions and logotype

* Removes unused style

* Fix lint

* Moves footer and header in "layout" level

* Makes the text container larger

* Fix lint

* Improves docs style

* Adds colors to brand palette

* Adds docs navigation list

* Improves footer

* Adds doc section for logos

* Adds vertical logo version

* Fix layout docs

* Improves docs mixins

* Creates placeholder for buttons

* Creates separated components "faq"

* Renames the faq list

* Improves style colour palettes

* Adds faq list component dependency

* Rearranges brand colour palette

* Adds new docs sections to the navigation

* Organises layout components into mixins and separates templates

* Adds new docs sections and improves the older ones

* Reformats code and adds website mixins

* Changes structure of color-box block

* Uses templates and mixins to make the view modularized

* Improves style for footer and faqs

Author: andreamangano