我在output设置文件名占位符，打包出来也能打包出两个文件。
但是在index.html里面引用的还是boundle.js
最神奇的是，，居然还正常执行了

const path = require('path');
const htmlWebpackPlugin = require('html-webpack-plugin')
const cleanWebpackPlugin = require('clean-webpack-plugin')
module.exports = {
  mode: 'production',
  entry: {
    main: './src/index.js',
    sub: './src/index.js'

  },
  module: {
    rules: [{
      test: /\.jpg$/,
      use: [
        {
          loader: 'file-loader',
          options: {
            name: '[name].[ext]',
            outputPath: 'images/',
          }
        }]
    },
    {
      test: /\.(css|less)$/,
      use: ['style-loader', {
        loader: 'css-loader',
        options: {
          importLoaders: 2,
          modules: true,
        }
      }, 'less-loader', 'postcss-loader']
    },
    {
      test: /\.(eot|ttf|svg)$/,
      use: {
        loader: 'file-loader'
      }
    }
    ],
  },
  plugins: [
    new cleanWebpackPlugin(),
    new htmlWebpackPlugin({
      template: './src/index.html',
     
    }),
  
  ],
  output: {
    filename: '[name].js',
    path: path.resolve(__dirname, 'dist')
  }
}