Add @typescript-eslint/switch-exhaustiveness-check rule

https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/switch-exhaustiveness-check.md

Author: sindresorhus

index.js

@@ -395,6 +395,7 @@ module.exports = {
 		// 	}
 		// ],
 
+		'@typescript-eslint/switch-exhaustiveness-check': 'error',
 		'@typescript-eslint/triple-slash-reference': [
 			'error',
 			{