The right stuff
Contributing to the design system
This page explains the process (or processes) by which the design system gets updated
Describe who's involved in changes to the system. Describe who's expected to do the work and who approves changes.
Describe specifically the process or processes by which the system gets updated. What happens when existing component need modified? What if an entire new component needs created? What happens if a component is deprecated? See Canonical's fantastic decision tree for contributing changes to their design system.
Since a design system is made up of component code, guidelines, documentation, design tools, and resources, keep in mind you'll likely need to define several processes to contribute each of these ingredients.
Cross-linking to the support page is a good idea here.