feat: system prompt (#448)

embedchain/apps/Llama2App.py

@@ -2,7 +2,7 @@ import os
 
 from langchain.llms import Replicate
 
-from embedchain.config import AppConfig
+from embedchain.config import AppConfig, ChatConfig
 from embedchain.embedchain import EmbedChain
 
 
@@ -27,8 +27,10 @@ class Llama2App(EmbedChain):
 
         super().__init__(config)
 
-    def get_llm_model_answer(self, prompt, config: AppConfig = None):
+    def get_llm_model_answer(self, prompt, config: ChatConfig = None):
         # TODO: Move the model and other inputs into config
+        if config.system_prompt:
+            raise ValueError("Llama2App does not support `system_prompt`")
         llm = Replicate(
             model="a16z-infra/llama13b-v2-chat:df7690f1994d94e96ad9d568eac121aecf50684a0b0963b25a41cc40061269e5",
             input={"temperature": 0.75, "max_length": 500, "top_p": 1},