[OUDS] Add a page linking tokens and our utilities

[louismaximepiton]

Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

Maybe a page situated as the landing page of utilities, but the idea is to have somewhere in the doc an explanation about how to use an utility when there is a token applied in the design, what are the equivalences, ...

Motivation and context

Help user understand the link between the design tokens and our utilities.