code: function showHelp() {
      var usage = "usage: \n";
      for (var p in commands) {
          if (typeof commands[p] !== "function") {
              usage += "\t " + p + "\t " + commands[p].alias + "\t " + commands[p].desc + "\n ";
          };
      };
  
      usage += "\nexamples: ";
      usage += "\n\n $node index.js --export\n\tthis will export all files configed to json.";
      usage += "\n\n $node index.js --export ./excel/foo.xlsx ./excel/bar.xlsx\n\tthis will export foo and bar xlsx files.";
  
      console.log(usage);
  }
docs: show help