message: updated export file name
diff: @@ -17,7 +17,7 @@ pptx.writeFile("react-demo.pptx");`;
  let pptx = new pptxgen();
  let slide = pptx.addSlide();
  slide.addText("React Demo!", { x: 1, y: 1, w: "80%", h: 1, fontSize: 36, fill: "eeeeee", align: "center" });
  - pptx.writeFile("react-demo.pptx");
  + pptx.writeFile("pptxgenjs-demo-react.pptx");
  console.log(`pptx.version = ${pptx.version}`);
  }
  