UI Package
Principal purpose of ui package is to host individual and reusable ui components (even outside of web3modal codebases).
Secondary purpose of this package is to expose shared utilities related to "ui logic".
Assets
Contain assets like images, fonts etc. used by ui components
Components
Simple, stateless, single purpose components like icon, button etc.
Composites
More complex components that compose multiple simple components or have internal state i.e tabs
Layout
Components like flex, grid, container responsible for layouts.