Update handbook link in readme (#43813)
Update handbook link in readme (#43813)

Co-authored-by: Andrew Thongsavath <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@athongsavath.com>
kitsonk/TypeScript,SaschaNaz/TypeScript,Microsoft/TypeScript,Microsoft/TypeScript,Microsoft/TypeScript,weswigham/TypeScript,RyanCavanaugh/TypeScript,weswigham/TypeScript,RyanCavanaugh/TypeScript,SaschaNaz/TypeScript,RyanCavanaugh/TypeScript,microsoft/TypeScript,weswigham/TypeScript,SaschaNaz/TypeScript,kitsonk/TypeScript,kpreisser/TypeScript,microsoft/TypeScript,microsoft/TypeScript,kitsonk/TypeScript,kpreisser/TypeScript,kpreisser/TypeScript,SaschaNaz/TypeScript