switch to typescript

rollup.server.config.js

@@ -0,0 +1,13 @@
+// rollup.config.js
+import typescript from 'rollup-plugin-typescript2';
+
+export default {
+  input: 'src/server/main.ts',
+  output: {
+    dir: 'build/server',
+    format: 'es',
+  },
+  plugins: [typescript({
+    "tsconfig": "tsconfig.server.json"
+  })],
+};