Fix typos

app.py

@@ -343,7 +343,7 @@ with gr.Blocks() as demo:
             # cache_examples=True
                 ),
     with gr.Tab("Compare between versions"):
-        btn_com = gr.Button(value="Differnces highlighting")
+        btn_com = gr.Button(value="Differences Highlighting")
         btn_com.click(fn=copy_to_clipboard, inputs=[output_1], outputs=[])
         with gr.Row():
             com_1 = gr.Textbox(label="Non-update Article", lines=25)