docs: update Readme

Author: pythops

README.md

@@ -52,9 +52,11 @@ Tenere can be configured using a TOML configuration file. The file should be loc
 Here are the available general settings:
 
 - `archive_file_name`: the file name where the chat will be saved. By default it is set to `tenere.archive`
+- `model`: the llm model name. Currently only `chatgpt` is supported.
 
 ```toml
 archive_file_name = "tenere.archive"
+model = "chatgpt"
 
 ```
 
@@ -72,7 +74,7 @@ new_chat = 'n'
 save_chat = 's'
 ```
 
-### Chatgpt API
+## Chatgpt
 
 To use Tenere's chat functionality, you'll need to provide an API key for OpenAI. There are two ways to do this:
 
@@ -85,9 +87,10 @@ export OPENAI_API_KEY="YOUTR KEY HERE"
 2. Include your API key in the configuration file:
 
 ```toml
-[gpt]
+[chatgpt]
 openai_api_key = "Your API key here"
-model = "the chat model name" # <- Optional field
+model = "gpt-3.5-turbo"
+url = "https://api.openai.com/v1/chat/completions"
 ```
 
 The default model is set to `gpt-3.5-turbo`. check out the [OpenAI documentation](https://platform.openai.com/docs/models/gpt-3-5) for more info.