Fix typo (#986)

"Lightning" not "Lightening"

docs/source/blogs_and_press.rst

@@ -2,6 +2,6 @@ Blogs and Press
 =================
 
 1. `Hugging Face with ZeRO <https://huggingface.co/blog/zero-deepspeed-fairscale>`_
-2. `Pytorch Lightening <https://medium.com/pytorch/pytorch-lightning-1-1-model-parallelism-training-and-more-logging-options-7d1e47db7b0b>`_
+2. `Pytorch Lightning <https://medium.com/pytorch/pytorch-lightning-1-1-model-parallelism-training-and-more-logging-options-7d1e47db7b0b>`_
 3. `MMT <https://about.fb.com/news/2020/10/first-multilingual-machine-translation-model/>`_
 4. `SEER <https://ai.facebook.com/blog/seer-the-start-of-a-more-powerful-flexible-and-accessible-era-for-computer-vision/>`_