[11.x] update docs to include ddJson() (#10178)

* updated docs with `ddJson()`

* Update http-tests.md

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: chester-sykes

http-tests.md

@@ -303,7 +303,7 @@ class ExampleTest extends TestCase
 }
 ```
 
-Alternatively, you may use the `dd`, `ddHeaders`, and `ddSession` methods to dump information about the response and then stop execution:
+Alternatively, you may use the `dd`, `ddHeaders`, `ddSession`, and `ddJson` methods to dump information about the response and then stop execution:
 
 ```php tab=Pest
 <?php
@@ -312,9 +312,8 @@ test('basic test', function () {
     $response = $this->get('/');
 
     $response->ddHeaders();
-
     $response->ddSession();
-
+    $response->ddJson();
     $response->dd();
 });
 ```