Fix storybook framer motion interaction

.storybook/main.js

@@ -8,4 +8,20 @@ module.exports = {
     },
   ],
   framework: '@storybook/react',
+  webpackFinal: async (config, { configType }) => {
+    // `configType` has a value of 'DEVELOPMENT' or 'PRODUCTION'
+    // You can change the configuration based on that.
+    // 'PRODUCTION' is used when building the static version of storybook.
+
+    // https://github.com/polkadot-js/extension/issues/621#issuecomment-759341776
+    // framer-motion uses the .mjs notation and we need to include it so that webpack will
+    // transpile it for us correctly (enables using a CJS module inside an ESM).
+    config.module.rules.push({
+      test: /\.mjs$/,
+      include: /node_modules/,
+      type: 'javascript/auto',
+    });
+    // Return the altered config
+    return config;
+  },
 };