Restructured and optimized web brand guide

Changes in this release

• added additional brand colourways to the root code
• added site breadcrumbs to header
• added current page to breadcrumb structure before selected tab
• increased font scaling on all areas of the web brand guide
• impoved the content card colours
• replaced minimum font size of 0.8125 with 0.875rem
• increased icon and outlined tag sizes for better visibility and proportions
• reordered into logical grouping: Colours, Typography, Components, Code, Reference