add webaudio cjs + esm build task

packages/webaudio/package.json

@@ -2,13 +2,16 @@
   "name": "@strudel.cycles/webaudio",
   "version": "0.3.2",
   "description": "Web Audio helpers for Strudel",
-  "main": "index.mjs",
+  "main": "dist/index.cjs.mjs",
+  "module": "dist/index.es.js",
   "type": "module",
   "directories": {
     "example": "examples"
   },
   "scripts": {
-    "example": "npx parcel examples/repl.html"
+    "example": "npx parcel examples/repl.html",
+    "build": "vite build",
+    "prepublish": "npm run build"
   },
   "repository": {
     "type": "git",

packages/webaudio/vite.config.js

@@ -0,0 +1,19 @@
+import { defineConfig } from 'vite';
+import { dependencies } from './package.json';
+import { resolve } from 'path';
+
+// https://vitejs.dev/config/
+export default defineConfig({
+  plugins: [],
+  build: {
+    lib: {
+      entry: resolve(__dirname, 'index.mjs'),
+      formats: ['es', 'cjs'],
+      fileName: (ext) => `index.${ext}.js`,
+    },
+    rollupOptions: {
+      external: [...Object.keys(dependencies)],
+    },
+    target: 'esnext',
+  },
+});