Update app.py

Minor update in comments.

app.py

@@ -79,7 +79,7 @@ with gr.Blocks() as demo:
         # Retrieval (ColBERT) + Generation (DSPy & Mistral)
         - Note:
             - building the retrieval model will be slow on **free CPU** (expect 5+ minutes).
-            - first question/answer will be slow (2 minutes for model loading). Subsequent question (approx. 10 seconds)
+            - first question & answer will be slow (2 minutes for model loading). Subsequent question approx. 10 seconds.
         - Usage: upload a few PDF files to index. Build the model. Ask questions.
     """)