update the history docs

app.py

@@ -60,7 +60,7 @@ if prompt := st.chat_input("What is up?"):
     if not prompt.__contains__("Yes") or not prompt.__contains__("No"):
         docs = oracle_db(prompt, 5)
         if len(history_docs) == 3:
-            history_docs = []
+            history_docs.pop(0) 
             history_docs.append(docs)
         else:
             history_docs.append(docs)