doc(ExpectAPI): improve doc on extend (#11211)

Author: ajubin

docs/ExpectAPI.md

@@ -67,7 +67,7 @@ test('numeric ranges', () => {
 });
 ```
 
-_Note_: In TypeScript, when using `@types/jest` for example, you can declare the new `toBeWithinRange` matcher like this:
+_Note_: In TypeScript, when using `@types/jest` for example, you can declare the new `toBeWithinRange` matcher in the imported module like this:
 
 ```ts
 declare global {