Updating documentation for the new configuration variables introduced

and adding comments for some code handleing new js files.
Signed-off-by: Piyush Vijay <piyushvijay.1997@gmail.com>

.jshintrc

@@ -5,6 +5,9 @@
     // Globals
     "jquery" : true,
 
+    // ES6
+    "esversion": 6,
+
     // Stricter checking
     "curly" : true,
     "immed" : true,

doc/config.rst

@@ -3402,6 +3402,21 @@ Developer
 
     These settings might have huge effect on performance or security.
 
+.. config:option:: $cfg['environment']
+
+    :type: string
+    :default: `'production'`
+
+    Enable you to set the working environment for loading js files
+
+.. config:option:: $cfg['webpack_port']
+
+    :type: integer
+    :default: 3307
+
+    Enable you to start webpack development server for serving js files
+    when woking in the development environment
+
 .. config:option:: $cfg['DBG']
 
     :type: array

js/ajax.js

@@ -639,9 +639,13 @@ var AJAX = {
             var self = this;
 
             script.type = 'text/javascript';
-            /* new directory */
+            /**
+             * This piece of code is for appending the new revamped files into the
+             * DOM so that both new and old files can be used simultaneously
+             * It checks whether the file contains new in its name or not
+             */
             var check = name.split('_');
-            if (check[check.length - 1] === 'new') {
+            if (check[check.length - 1] === 'new.js') {
                 var script_src = '';
                 if (PMA_commonParams.get('environment') === 'development') {
                     script_src += 'http://localhost:' + PMA_commonParams.get('webpack_port') + '/js/dist/';
@@ -652,7 +656,6 @@ var AJAX = {
             } else {
                 script.src = 'js/' + name + '?' + 'v=' + encodeURIComponent(PMA_commonParams.get('PMA_VERSION'));
             }
-            /* new directory */
             script.async = false;
             script.onload = function () {
                 self.done(name, callback);

libraries/classes/Scripts.php

@@ -54,15 +54,18 @@ private function _includeFiles(array $files)
                     . "type='text/javascript' src='js/" . $file_name
                     . "'></script>\n";
             } else if (strpos($value['filename'], "_new") !== false) {
-                /* new directory */
+                /**
+                 * This piece of code is for appending the new revamped files into the
+                 * DOM so that both new and old files can be used simultaneously
+                 * It checks whether the file contains new in its name or not
+                 */
                 if ($GLOBALS['cfg']['environment'] === 'development') {
                     $src = "http://localhost:" . $GLOBALS['cfg']['webpack_port'] . "/";
                 } else if ($GLOBALS['cfg']['environment'] === 'production'){
                     $src = "";
                 }
                 $result .= '<script data-cfasync="false" type="text/javascript" src="' . $src . 'js/dist/'
                     .  $value['filename'] . '?' . Header::getVersionParameter() . '"></script>' . "\n";
-                /* new directory */
             } else {
                 $result .= '<script data-cfasync="false" type="text/javascript" src="js/'
                     . $value['filename'] . '?' . Header::getVersionParameter() . '"></script>' . "\n";