Bundle code for the map on the homepage

site/build.js

@@ -1,10 +1,14 @@
 import Metalsmith from 'metalsmith';
+import common from '@rollup/plugin-commonjs';
 import inPlace from '@metalsmith/in-place';
 import layouts from '@metalsmith/layouts';
 import markdown from '@metalsmith/markdown';
-import {dirname} from 'node:path';
+import {dirname, resolve} from 'node:path';
 import {env} from 'node:process';
 import {fileURLToPath} from 'node:url';
+import {nodeResolve} from '@rollup/plugin-node-resolve';
+import {rollup} from 'rollup';
+import {terser} from 'rollup-plugin-terser';
 
 const baseDir = dirname(fileURLToPath(import.meta.url));
 
@@ -19,8 +23,34 @@ const builder = Metalsmith(baseDir)
   .use(markdown())
   .use(layouts());
 
-builder.build((err) => {
+builder.build(async (err) => {
   if (err) {
     throw err;
   }
+  await bundleMain();
 });
+
+async function bundleMain() {
+  const inputOptions = {
+    plugins: [
+      common(),
+      nodeResolve({
+        moduleDirectories: [
+          resolve(baseDir, '../src'),
+          resolve(baseDir, '../node_modules'),
+        ],
+      }),
+      terser(),
+    ],
+    input: resolve(baseDir, './build/main.js'),
+  };
+
+  const outputOptions = {
+    dir: resolve(baseDir, './build'),
+    format: 'iife',
+  };
+
+  const bundle = await rollup(inputOptions);
+  await bundle.write(outputOptions);
+  bundle.close();
+}