Update Together reference (#99)

# PR Summary
PR fixes the `Together` reference in `README.md`. The format of a link
in markdown is: `[text](link)`.

Signed-off-by: Emmanuel Ferdman <emmanuelferdman@gmail.com>

README.md

@@ -200,7 +200,7 @@ Example:
 openai_base_url: https://your-custom-api-url.com/v1
 ```
 
-Use `oai-compat:` prefix for the model name to pass non-GPT model names to the API. For example, to chat with Llama3-70b on [https://together.ai](Together), use the following command:
+Use `oai-compat:` prefix for the model name to pass non-GPT model names to the API. For example, to chat with Llama3-70b on [Together](https://together.ai), use the following command:
 
 ```bash
 OPENAI_API_KEY=$TOGETHER_API_KEY OPENAI_BASE_URL=https://api.together.xyz/v1 gpt general --model oai-compat:meta-llama/Llama-3-70b-chat-hf