Add to example configuration.

config/config.example.yml

@@ -168,6 +168,10 @@ browseBy:
   fiveYearLimit: 30
   # The absolute lowest year to display in the dropdown (only used when no lowest date can be found for all items)
   defaultLowerLimit: 1900
+  # The number of entries in a paginated browse results list.
+  # Rounded to the nearest size in the list of selectable sizes on the
+  # settings menu.
+  pageSize: 20
 
 # Item Config
 item: