Add message on topic code model

pages/Topic_Code_Browser.py

@@ -110,7 +110,9 @@ topic_code_description = (
     " at different examples in the dataset (ExampleID) and finding codes that activate on some fraction"
     " of the tokens in that example (Recall Threshold). Decrease the Recall Threshold to view more possible"
     " topic codes and increase it to see fewer. Click “Find Next Example” to find the next example with at"
-    " least one code firing on that example above the Recall Threshold."
+    " least one code firing on that example above the Recall Threshold.\n\n"
+    "Topic codes are displayed for the codebook model selected on the Code Browser page. To view topic codes"
+    " for a different model, go to the Code Browser page and select a different model."
 )
 st.write(topic_code_description)