added app.py

app.py

@@ -0,0 +1,12 @@
+import time
+import gradio as gr
+
+def slow_echo(message, history):
+    for i in range(len(message)):
+        time.sleep(0.3)
+        yield "You typed: " + message[: i+1]
+
+gr.ChatInterface(
+    fn=slow_echo, 
+    type="messages"
+).launch()