Amend main module code in modding guide

docs/guides/modding-guide.rst

@@ -457,6 +457,8 @@ Ok, you're all set up! Now, let's take a look at an example
     enabled = enabled or false
 
     function isEnabled()
+        -- this function is for the enabled API, the script won't show up on the
+        -- control panel without it
         return enabled
     end
 
@@ -473,6 +475,10 @@ Ok, you're all set up! Now, let's take a look at an example
         dfhack.run_command('enable', 'example-mod')
     end
 
+    if dfhack_flags.module then
+        return
+    end
+
     if not dfhack_flags.enable then
         print(dfhack.script_help())
         print()