docs: 📝 add testing library docs

docs/302-recipe-search-integration.md

@@ -4,7 +4,7 @@
 git checkout origin/testing-303-recipe-search-integration-starter
 ```
 
-# 🎯 Goal: Test `<wm-recipe-search>`
+# 🎯 Goal #1: Test `<wm-recipe-search>`
 
 Same goal as [previous exercise](301-recipe-search-isolated.md) _(i.e. `<wm-recipe-search>` should call `RecipeRepository.search()` on startup.)_
 
@@ -37,6 +37,23 @@ pnpm test --watch
 
 3. Checkout the implementation as mentioned at step 0 if you didn't do it already.
 
+# 🎯 Goal #2: Test `<wm-recipe-search>` using `@testing-library/angular`
+
+Refactor the previous test using `@testing-library/angular` instead of `TestBed`.
+
+## 🍴 Cutleries
+- [render](https://testing-library.com/docs/angular-testing-library/api#render)
+- `configureTestBed` option:
+```ts
+render(..., {
+  configureTestBed(testBed) {
+    testBed.inject(MyService).doSomething()
+  }
+});
+```
+- [queries](https://testing-library.com/docs/queries/about/)
+
+
 # Appendices
 
 ## 🎁 Tip: Query DOM with `fixture.debugElement`