Add missing description to CONTRIBUTING.md (#40329)
Add missing description to CONTRIBUTING.md (#40329)


kitsonk/TypeScript,RyanCavanaugh/TypeScript,kpreisser/TypeScript,RyanCavanaugh/TypeScript,kpreisser/TypeScript,kitsonk/TypeScript,kpreisser/TypeScript,SaschaNaz/TypeScript,microsoft/TypeScript,SaschaNaz/TypeScript,weswigham/TypeScript,SaschaNaz/TypeScript,microsoft/TypeScript,Microsoft/TypeScript,Microsoft/TypeScript,SaschaNaz/TypeScript,kitsonk/TypeScript,Microsoft/TypeScript,RyanCavanaugh/TypeScript,weswigham/TypeScript,weswigham/TypeScript,microsoft/TypeScript