Templating: Add generation prompt appending

Append generation prompts if given the flag on an OAI chat completion
request.

This appends the "assistant" message to the instruct prompt. Defaults
to true since this is intended behavior.

Signed-off-by: kingbri <bdashore3@proton.me>

OAI/types/chat_completion.py

@@ -26,6 +26,7 @@ class ChatCompletionRequest(CommonCompletionRequest):
     # Take in a string as well even though it's not part of the OAI spec
     messages: Union[str, List[Dict[str, str]]]
     prompt_template: Optional[str] = None
+    add_generation_prompt: Optional[bool] = True
 
 class ChatCompletionResponse(BaseModel):
     id: str = Field(default_factory=lambda: f"chatcmpl-{uuid4().hex}")