feat(unicorn): Create Unicorn Icon theme

[ajstrongdev]

https://github.com/rhino-linux/tracker/issues/16

ajstrongdev created this issue in rhino-linux/tracker

open feat(unicorn): Create Unicorn Icon theme #16

Quite a large task. We need a unified Icon theme for Rhino Linux. **Specification:** - Must have a border gradient that pulls from the primary colours of the icon - Must have a darkened background gradient that pulls from colours utilised on the border. - Must have a candy designed icon in the centre - Must be rounded squircles, similar to icons found in macOS Big Sur+