chore: add behavior item initialize to entry point

webpack.client.config.js

@@ -8,6 +8,7 @@ config.entry = {
   client: [
     '@babel/polyfill',
     path.join(__dirname, 'register-traits.js'),
+    '@avocado/behavior/item/initialize',
     path.join(__dirname, 'client', 'index.js'),
   ],
 };

webpack.server.config.js

@@ -10,6 +10,7 @@ config.entry = {
     'source-map-support/register',
     '@babel/polyfill',
     path.join(__dirname, 'register-traits.js'),
+    '@avocado/behavior/item/initialize',
     path.join(__dirname, 'server', 'index.js'),
   ],
 };