Fix missing hook method types for TypeScript (#353)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

source/index.ts

@@ -28,6 +28,6 @@ const ky = createInstance();
 export default ky;
 
 export {Options};
-
+export {BeforeRequestHook, BeforeRetryHook, AfterResponseHook} from './types/hooks.js';
 export {HTTPError} from './errors/HTTPError.js';
 export {TimeoutError} from './errors/TimeoutError.js';