chore: add comments

Author: xiazeyu

lib/clL2D.0.min.js

@@ -17,6 +17,9 @@ import config from './lib/configManager.js';
  */
 
 export function init(userConfig){
+  if (process.env.NODE_ENV === 'development') {
+    console.log('Hey that, you are now in DEV.');
+  }
   try{
     config.checkConfig(userConfig);
   }catch(err){

lib/clL2D.0.min.js.map

@@ -14,6 +14,7 @@ module.exports = env => {return{
 
   output: {
     filename: 'clL2D.min.js',
+    // YOU MUST INSTALL babel-plugin-syntax-dynamic-import FIRST TO ENABLE CODE SPLITTING!
     chunkFilename: 'clL2D.[id].min.js',
     library: 'initL2Dwidget',
     libraryExport: 'init',