Part of #53322

What problem does this address?

One of the goals of the admin redesign project is to create a more consistent/seamless WordPress experience as users venture in and out of different plugins. A lot of plugin authors currently bypass core UI's (often for good reason) which creates this feeling of fragmentation.

What is your proposed solution?

We need to incentivise and educate plugin authors and core contributors around how to utilise the "system" in the best way possible. This includes guidelines around colour, page layout, components, patterns, accessibility etc.

As we start to flesh out the design system in more detail and execute on its various parts we need to look at iterating on the existing design handbook

-- WIP --