Add configuration for netlify builds to include demo files.

netlify.toml

@@ -3,4 +3,4 @@
 
 [[redirects]]
   from = "/"
-  to = "/__tests__/integration/mirador/"
+  to = "/dist/__tests__/integration/mirador/"

vite.config.js

@@ -1,7 +1,9 @@
 import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
 import fs from 'fs/promises';
+import path from 'node:path';
 import { fileURLToPath } from 'url';
+import { globSync } from 'fs';
 
 /**
 * Vite configuration
@@ -11,11 +13,24 @@ export default defineConfig({
     lib: {
       entry: './src/index.js',
       fileName: (format) => (format === 'umd' ? 'mirador.js' : 'mirador.es.js'),
-      formats: ['es', 'umd'],
+      formats: process.env.NETLIFY ? ['es'] : ['es', 'umd'],
       name: 'Mirador',
     },
     rollupOptions: {
       external: ['__tests__/*', '__mocks__/*'],
+      input: process.env.NETLIFY ? Object.fromEntries(
+        globSync('./__tests__/integration/mirador/*.html').map((file) => [
+          // This remove `src/` as well as the file extension from each
+          // file, so e.g. src/nested/foo.js becomes nested/foo
+          path.relative(
+            '__tests__/integration/mirador',
+            file.slice(0, file.length - path.extname(file).length),
+          ),
+          // This expands the relative paths to absolute paths, so e.g.
+          // src/nested/foo becomes /project/src/nested/foo.js
+          fileURLToPath(new URL(file, import.meta.url)),
+        ]),
+      ) : undefined,
       output: {
         assetFileNames: 'mirador.[ext]',
       },