Improve demo wording, error fallback

demo.py

@@ -5,8 +5,12 @@ import gradio as gr
 def submit(inputs):
     if not inputs:
         return
+
     payload = {"content": inputs, "author": "anna nymous"}
-    httpx.post("http://localhost:8080/submit/", json=payload)
+    try:
+        httpx.post("http://localhost:8080/submit/", json=payload)
+    except httpx.ConnectError:
+        pass
 
 
 def check_status():
@@ -67,7 +71,7 @@ Input currently supports:
 - plain text
 - a URL to a webpage
 - a URL to a youtube video (the video will be transcribed)
-- a URL to an image (the image description will be used)
+- a URL to an image (url ending in .png, .jpg, etc.; the image description will be used)
 """