don't bundle ES module

bundling entire library into one ES module disables tree-shaking in Webpack

Author: frysztak

package.json

@@ -3,7 +3,7 @@
     "version": "3.7.0",
     "description": "An open source and production-ready motion library for React on the web",
     "main": "dist/framer-motion.cjs.js",
-    "module": "dist/framer-motion.es.js",
+    "module": "dist/es/index.js",
     "types": "types/index.d.ts",
     "author": "Framer Motion",
     "license": "MIT",

rollup.config.js

@@ -63,9 +63,10 @@ const cjs = Object.assign({}, config, {
 
 const es = Object.assign({}, config, {
     output: {
-        file: `dist/${pkg.name}.es.js`,
         format: "es",
         exports: "named",
+        preserveModules: true,
+        dir: "dist/es",
     },
     plugins: [resolve()],
     external,