fix: testing library docs (#15667)

Author: nattui

docs/guides/test/testing-library.md

@@ -49,7 +49,7 @@ Next, add these preload scripts to your `bunfig.toml` (you can also have everyth
 
 ```toml#bunfig.toml
 [test]
-preload = ["happydom.ts", "testing-library.ts"]
+preload = ["./happydom.ts", "./testing-library.ts"]
 ```
 ---
 
@@ -84,4 +84,4 @@ test('Can use Testing Library', () => {
 
 ---
 
-Refer to the [Testing Library docs](https://testing-library.com/), [Happy DOM repo](https://github.com/capricorn86/happy-dom) and [Docs > Test runner > DOM](https://bun.sh/docs/test/dom) for complete documentation on writing browser tests with Bun.
+Refer to the [Testing Library docs](https://testing-library.com/), [Happy DOM repo](https://github.com/capricorn86/happy-dom) and [Docs > Test runner > DOM](https://bun.sh/docs/test/dom) for complete documentation on writing browser tests with Bun.