docs: add Frequently Asked Questions to README.md (#462)

* docs: add Frequently Asked Questions to README.md

* Update README.md

Co-authored-by: Alexander Baranov <[email protected]>

---------

Co-authored-by: Alexander Baranov <[email protected]>

Author: vvatanabe

README.md

@@ -694,6 +694,37 @@ OPENAI_TOKEN=XXX go test -v -tags=integration ./api_integration_test.go
 
 If the `OPENAI_TOKEN` environment variable is not available, integration tests will be skipped.
 
+## Frequently Asked Questions
+
+### Why don't we get the same answer when specifying a temperature field of 0 and asking the same question?
+
+Even when specifying a temperature field of 0, it doesn't guarantee that you'll always get the same response. Several factors come into play.
+
+1. Go OpenAI Behavior: When you specify a temperature field of 0 in Go OpenAI, the omitempty tag causes that field to be removed from the request. Consequently, the OpenAI API applies the default value of 1.
+2. Token Count for Input/Output: If there's a large number of tokens in the input and output, setting the temperature to 0 can still result in non-deterministic behavior. In particular, when using around 32k tokens, the likelihood of non-deterministic behavior becomes highest even with a temperature of 0.
+
+Due to the factors mentioned above, different answers may be returned even for the same question.
+
+**Workarounds:**
+1. Using `math.SmallestNonzeroFloat32`: By specifying `math.SmallestNonzeroFloat32` in the temperature field instead of 0, you can mimic the behavior of setting it to 0.
+2. Limiting Token Count: By limiting the number of tokens in the input and output and especially avoiding large requests close to 32k tokens, you can reduce the risk of non-deterministic behavior.
+
+By adopting these strategies, you can expect more consistent results.
+
+**Related Issues:**  
+[omitempty option of request struct will generate incorrect request when parameter is 0.](https://github.com/sashabaranov/go-openai/issues/9)
+
+### Does Go OpenAI provide a method to count tokens?
+
+No, Go OpenAI does not offer a feature to count tokens, and there are no plans to provide such a feature in the future. However, if there's a way to implement a token counting feature with zero dependencies, it might be possible to merge that feature into Go OpenAI. Otherwise, it would be more appropriate to implement it in a dedicated library or repository.
+
+For counting tokens, you might find the following links helpful:  
+- [Counting Tokens For Chat API Calls](https://github.com/pkoukk/tiktoken-go#counting-tokens-for-chat-api-calls)
+- [How to count tokens with tiktoken](https://github.com/openai/openai-cookbook/blob/main/examples/How_to_count_tokens_with_tiktoken.ipynb)
+
+**Related Issues:**  
+[Is it possible to join the implementation of GPT3 Tokenizer](https://github.com/sashabaranov/go-openai/issues/62)
+
 ## Thank you
 
 We want to take a moment to express our deepest gratitude to the [contributors](https://github.com/sashabaranov/go-openai/graphs/contributors) and sponsors of this project: