[JS] save txt file

(function () {
    var blob = new Blob(['content'], {type: 'text/plain; charset=utf-8'}),
        blobUrl = URL.createObjectURL(blob),
        node = document.createElement('a');
 
    node.href = blobUrl;
    node.download = 'testSave.txt';
 
    node.click();
}());