optimize template loading

src/main.rs

@@ -20,7 +20,7 @@ fn main() {
         specs::compile(&args.devices, &args.env.spec_path, dbg);
 
     for spec in specifications {
-        let result = tmpls::process_templates(&spec, dbg).ok().unwrap();
+        let result = RenderedConfig::from_spec(&spec, dbg).ok().unwrap();
         output_rendered_configs(result, &args.env.out_path, dbg)
     }
 }