Precompress static resources in node-adapter.

svelte.config.js

@@ -7,7 +7,9 @@ const config = {
     // By default, `npm run build` will create a standard Node app.
     // You can create optimized builds for different platforms by
     // specifying a different adapter
-    adapter: node(),
+    adapter: node({
+      precompress: true,
+    }),
 
     // hydrate the <div id="svelte"> element in src/app.html
     target: "#svelte",