doc: improve subtests documentation

PR-URL: nodejs#51379
Fixes: nodejs#51359
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>

doc/api/test.md

@@ -105,9 +105,12 @@ If any tests fail, the process exit code is set to `1`.
 
 ## Subtests
 
-The test context's `test()` method allows subtests to be created. This method
-behaves identically to the top level `test()` function. The following example
-demonstrates the creation of a top level test with two subtests.
+The test context's `test()` method allows subtests to be created.
+It allows you to structure your tests in a hierarchical manner,
+where you can create nested tests within a larger test.
+This method behaves identically to the top level `test()` function.
+The following example demonstrates the creation of a
+top level test with two subtests.
 
 ```js
 test('top level test', async (t) => {
@@ -121,9 +124,13 @@ test('top level test', async (t) => {
 });
 ```
 
+> **Note:** `beforeEach` and `afterEach` hooks are triggered
+> between each subtest execution.
+
 In this example, `await` is used to ensure that both subtests have completed.
 This is necessary because parent tests do not wait for their subtests to
-complete. Any subtests that are still outstanding when their parent finishes
+complete, unlike tests created with the `describe` and `it` syntax.
+Any subtests that are still outstanding when their parent finishes
 are cancelled and treated as failures. Any subtest failures cause the parent
 test to fail.