message: [skip ci] contributing TOC bullets
diff: 1. [Code style](#code-style)
  2. [Testing](#testing)
  - 1. [Code coverage](#code-coverage)
  + * [Code coverage](#code-coverage)
  3. [Tools we use](#tools-we-use)
  4. [Component patterns](#component-patterns)
  - 1. [Components with only system props](#components-with-only-system-props)
  - 1. [Primer CSS components](#primer-css-components)
  + * [Components with only system props](#components-with-only-system-props)
  + * [Primer CSS components](#primer-css-components)
  5. [Glossary](#glossary)
  ## Code Style
  