added extra features to repl.js

added more detailed help messages and added a 'helpC' command

lib/repl.js

@@ -1781,12 +1781,23 @@ function defineDefaultCommands(repl) {
         const line = `.${name}${cmd.help ? spaces + cmd.help : ''}\n`;
         this.output.write(line);
       });
+      this.output.write('\n in the Node.js REPL you may write regular JavaScript code\nand use REPL commands, the REPL commands are listed above\n')
       this.output.write('\nPress Ctrl+C to abort current expression, ' +
         'Ctrl+D to exit the REPL\n');
       this.displayPrompt();
     },
   });
-
+  repl.defineCommand('helpC', {
+    help: 'get help for a specific command',
+    action: function(cmd) {
+      if(this.commands[cmd]) {
+        this.output.write(cmd.help);
+      } else {
+        this.output.write('Command not found');
+      }
+      this.displayPrompt();
+    }
+  })
   repl.defineCommand('save', {
     help: 'Save all evaluated commands in this REPL session to a file',
     action: function(file) {
@@ -1801,7 +1812,7 @@ function defineDefaultCommands(repl) {
   });
 
   repl.defineCommand('load', {
-    help: 'Load JS from a file into the REPL session',
+    help: 'Load JS (variables, functions, etc) from a file into the REPL session',
     action: function(file) {
       try {
         const stats = fs.statSync(file);
@@ -1826,7 +1837,7 @@ function defineDefaultCommands(repl) {
   });
   if (repl.terminal) {
     repl.defineCommand('editor', {
-      help: 'Enter editor mode',
+      help: 'Enter editor mode (JS)',
       action() {
         _turnOnEditorMode(this);
         this.output.write(