[doc, data] fix: resolve broken documentation hyperlinks (verl-project#4970)

### What does this PR do?

Fix gsm8k datasets and tensordict hyperlink 404 not found.

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### Test

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### API and Usage Example

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```python
# Add code snippet or script demonstrating how to use this
```

### Design & Code Changes

- Changed 'https://huggingface.co/datasets/gsm8k' to
'https://huggingface.co/datasets/openai/gsm8k'
- Changed 'https://pytorch.org/tensordict/tutorials/data_fashion' to
'https://pytorch.org/tensordict/stable/tutorials/data_fashion'
- Changed 'https://pytorch.org/tensordict/overview.html' to
'https://pytorch.org/tensordict/stable/overview.html'

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Author: aphrodite1028

docs/api/data.rst

@@ -51,7 +51,7 @@ One can also index a tensordict along its batch_size. The contents of the Tensor
 
 For more about :class:`tensordict.TensorDict` usage, see the official tensordict_ documentation.
 
-.. _tensordict: https://pytorch.org/tensordict/overview.html
+.. _tensordict: https://pytorch.org/tensordict/stable/overview.html
 
 
 Core APIs

docs/examples/gsm8k_example.rst

@@ -10,7 +10,7 @@ In this example, we train an LLM to tackle the GSM8k task.
 
 Paper: https://arxiv.org/pdf/2110.14168
 
-Dataset: https://huggingface.co/datasets/gsm8k
+Dataset: https://huggingface.co/datasets/openai/gsm8k
 
 Note that the original paper mainly focuses on training a verifier (a
 reward model) to solve math problems via Best-of-N sampling. In this

docs/start/quickstart.rst

@@ -9,7 +9,7 @@ Post-train a LLM using GSM8K dataset.
 Introduction
 ------------
 
-.. _hf_dataset_gsm8k: https://huggingface.co/datasets/gsm8k
+.. _hf_dataset_gsm8k: https://huggingface.co/datasets/openai/gsm8k
 
 In this example, we train an LLM to tackle the `GSM8k <hf_dataset_gsm8k>`_ task with function-based rewards. [1]_
 

verl/protocol.py

@@ -810,7 +810,7 @@ def union(self, other: "DataProto") -> "DataProto":
 
     def make_iterator(self, mini_batch_size, epochs, seed=None, dataloader_kwargs=None):
         r"""Make an iterator from the DataProto. This is built upon that TensorDict can be used as a normal Pytorch
-        dataset. See https://pytorch.org/tensordict/tutorials/data_fashion for more details.
+        dataset. See https://pytorch.org/tensordict/stable/tutorials/data_fashion for more details.
 
 
         Args: