notes on OpenAI key being optional when using Entra ID

README.md

@@ -238,7 +238,7 @@ Note: settings starting with `AZURE_SEARCH` are only needed when using Azure Ope
 |AZURE_OPENAI_MODEL||The name of your model deployment|
 |AZURE_OPENAI_ENDPOINT||The endpoint of your Azure OpenAI resource (only one of AZURE_OPENAI_RESOURCE/AZURE_OPENAI_ENDPOINT is required)|
 |AZURE_OPENAI_MODEL_NAME|gpt-35-turbo-16k|The name of the model|
-|AZURE_OPENAI_KEY||One of the API keys of your Azure OpenAI resource|
+|AZURE_OPENAI_KEY||One of the API keys of your Azure OpenAI resource (optional if using Entra ID)|
 |AZURE_OPENAI_TEMPERATURE|0|What sampling temperature to use, between 0 and 2. Higher values like 0.8 will make the output more random, while lower values like 0.2 will make it more focused and deterministic. A value of 0 is recommended when using your data.|
 |AZURE_OPENAI_TOP_P|1.0|An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. We recommend setting this to 1.0 when using your data.|
 |AZURE_OPENAI_MAX_TOKENS|1000|The maximum number of tokens allowed for the generated answer.|