chore: correct entry point in webpack config

Author: lukewalczak

example/webpack.config.js

@@ -9,6 +9,8 @@ const node_modules = path.join(__dirname, 'node_modules');
 module.exports = async function (env, argv) {
   const config = await createExpoWebpackConfigAsync(env, argv);
 
+  config.entry = path.join(__dirname, 'index.js');
+
   config.module.rules.push({
     test: /\.(js|ts|tsx)$/,
     include: path.resolve(root, 'src'),