Server render the main page

Also, add hashes to asset file names and use the "entry manifest" plugin
in dev to get auto-reloading.

modules/utils/getEntryPoints.js

@@ -0,0 +1,19 @@
+import invariant from 'invariant';
+
+// Virtual module id; see rollup.config.js
+import entryManifest from 'entry-manifest';
+
+export default function getEntryPoints(entryName, formatKeys) {
+  const manifest = entryManifest[entryName];
+
+  invariant(manifest, 'Invalid entry name: %s', entryName);
+
+  return manifest.reduce((memo, entryPoint) => {
+    if (entryPoint.format in formatKeys) {
+      const key = formatKeys[entryPoint.format];
+      memo[key] = entryPoint.url;
+    }
+
+    return memo;
+  }, {});
+}