better defaults + update readme

src/convert.rs

@@ -101,7 +101,8 @@ fn recover_mods_into_server_ini(opts: &ConvertOptions<'_>, world_root: &Path) ->
 
     let Some(workshop_dir) = opts.workshop_dir else {
         eprintln!(
-            "Warning: --workshop-dir not set; wrote Mods= only. Pass a Steam workshop content/108600 path to also fill WorkshopItems="
+            "Warning: no workshop dir (pass --workshop-dir or place mods under \
+             <output>/../server-files/steamapps/workshop/content/108600); wrote Mods= only"
         );
         let mods_line = mod_ids.join(";");
         let ini = opts.output.join("Server").join(format!("{}.ini", opts.server_name));