Integrate with Fields module

[eliot-akira]

How to integrate the design library with the Fields module, a React-based form fields library. There are some components in common, like Checkbox and Switch.

The fields are currently used by Tangible Blocks for block controls:

• https://docs.loopsandlogic.com/tangible-blocks/block-controls/#control-types

In the template system, they will be used for WordPress content types and fields, custom post types and database tables, similar to Advanced Custom Fields.

Unifying all fields with the design system means:

• Incrementally update existing styles to use a shared set of design tokens and primitives.

For example, replace literal value 8px with Sass variable $space-2, or #abcdef with $theme-primary-color.

[eliot-akira]

Part of:

• #7