docs: pin some linked ipynb to 2.1.0

Author: Borda

docs/source-pytorch/advanced/post_training_quantization.rst

@@ -126,7 +126,7 @@ At last, the quantized model can be saved by:
 Hands-on Examples
 *****************
 
-Based on the `given example code <https://lightning.ai/docs/pytorch/stable/notebooks/lightning_examples/text-transformers.html>`_, we show how Intel Neural Compressor conduct model quantization on PyTorch Lightning. We first define the basic config of the quantization process.
+Based on the `given example code <https://lightning.ai/docs/pytorch/2.1.0/notebooks/lightning_examples/text-transformers.html>`_, we show how Intel Neural Compressor conduct model quantization on PyTorch Lightning. We first define the basic config of the quantization process.
 
 .. code-block:: python
 

docs/source-pytorch/starter/style_guide.rst

@@ -219,5 +219,5 @@ This is true for both academic and corporate settings where data cleaning and ad
 of iterating through ideas.
 
 - Check out the live examples to get your hands dirty:
-- `Introduction to PyTorch Lightning <https://lightning.ai/docs/pytorch/stable/notebooks/lightning_examples/mnist-hello-world.html>`_
+- `Introduction to PyTorch Lightning <https://lightning.ai/docs/pytorch/2.1.0/notebooks/lightning_examples/mnist-hello-world.html>`_
 - `Introduction to DataModules <https://lightning.ai/docs/pytorch/stable/notebooks/lightning_examples/datamodules.html>`_