PyTorch tips for better training performance (rasbt#525)

* PyTorch tips for better training performance

* formatting

* pep 8

Author: rasbt

README.md

@@ -121,6 +121,7 @@ Several folders contain optional materials as a bonus for interested readers:
   - [Llama 3.2 From Scratch](ch05/07_gpt_to_llama/standalone-llama32.ipynb)
   - [Memory-efficient Model Weight Loading](ch05/08_memory_efficient_weight_loading/memory-efficient-state-dict.ipynb)
   - [Extending the Tiktoken BPE Tokenizer with New Tokens](ch05/09_extending-tokenizers/extend-tiktoken.ipynb)
+  - [PyTorch Performance Tips for Faster LLM Training](ch05/10_llm-training-speed)
 - **Chapter 6: Finetuning for classification**
   - [Additional experiments finetuning different layers and using larger models](ch06/02_bonus_additional-experiments)
   - [Finetuning different models on 50k IMDB movie review dataset](ch06/03_bonus_imdb-classification)