Fix QA sample (#16648)

* fix QA sample

* For TF_QUESTION_ANSWERING_SAMPLE
Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

src/transformers/utils/doc.py

@@ -207,7 +207,8 @@ PT_QUESTION_ANSWERING_SAMPLE = r"""
 
     ```python
     >>> # target is "nice puppet"
-    >>> target_start_index, target_end_index = torch.tensor([14]), torch.tensor([15])
+    >>> target_start_index = torch.tensor([{qa_target_start_index}])
+    >>> target_end_index = torch.tensor([{qa_target_end_index}])
 
     >>> outputs = model(**inputs, start_positions=target_start_index, end_positions=target_end_index)
     >>> loss = outputs.loss
@@ -667,7 +668,8 @@ TF_QUESTION_ANSWERING_SAMPLE = r"""
 
     ```python
     >>> # target is "nice puppet"
-    >>> target_start_index, target_end_index = tf.constant([14]), tf.constant([15])
+    >>> target_start_index = tf.constant([{qa_target_start_index}])
+    >>> target_end_index = tf.constant([{qa_target_end_index}])
 
     >>> outputs = model(**inputs, start_positions=target_start_index, end_positions=target_end_index)
     >>> loss = tf.math.reduce_mean(outputs.loss)
@@ -1054,6 +1056,8 @@ def add_code_sample_docstrings(
     output_type=None,
     config_class=None,
     mask="[MASK]",
+    qa_target_start_index=14,
+    qa_target_end_index=15,
     model_cls=None,
     modality=None,
     expected_output="",
@@ -1078,6 +1082,8 @@ def add_code_sample_docstrings(
             processor_class=processor_class,
             checkpoint=checkpoint,
             mask=mask,
+            qa_target_start_index=qa_target_start_index,
+            qa_target_end_index=qa_target_end_index,
             expected_output=expected_output,
             expected_loss=expected_loss,
         )