Google Sheet script that will convert cells A2:B1000 into a downloadable XML file.

manufacturers.js

function doGet() {
  // The sheet that contains the manufacturer information.
  var manufacturerDataSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Manufacturers");
  // The first row of the sheet that contains the manufacturer's name and description.
  var manufacturerAttributes = manufacturerDataSheet.getRange("A1:B1").getValues();
  // Range of rows and columns that contain the manufacturer information.
  var manufacturerData = manufacturerDataSheet.getRange("A2:B1000").getValues();
  // XML document object.
  var document = XmlService.createDocument();
  // Root element of the XML output.
  var root = XmlService.createElement('manufacturers');
  // variable that holds the generated XML document.
  var xmlOutput;
  
  for(var i = 0; i < manufacturerData.length; i++) {
    
    if(!isEnd(manufacturerData[i])) {
      
      // Begin manufacturer tag.
      var manufacturer = XmlService.createElement('manufacturer');
      
      for(var j = 0; j < manufacturerData[i].length; j++) {
        
        var tag = manufacturerAttributes[0][j];
        var text = manufacturerData[i][j];
        var manufacturerAttribute = XmlService.createElement(tag);
        
        if(tag == "description") {
          
          manufacturerAttribute.addContent(XmlService.createCdata(text))
          
        } else {
          
          manufacturerAttribute.setText(text);
          
        }
        
        manufacturer.addContent(manufacturerAttribute);
        
      }
      
      root.addContent(manufacturer);
      
    } else {
      
      break;
      
    }
    
  }
  
  // Put everything together and output it.
  document.addContent(root);
  xmlOutput = XmlService.getPrettyFormat().format(document);
  Logger.log(xmlOutput);
  return ContentService.createTextOutput(xmlOutput).downloadAsFile("manufacturers.xml");
  
}

function isEnd(row) {
  
  for(var i = 0; i < row.length; i++) {
    
    if(row[i] != "") {
      
      return false;
      
    }
    
  }
  
  return true;
}