Made demo files into typescript files

demo/demo14.ts

@@ -0,0 +1,28 @@
+// Page numbers
+// Import from 'docx' rather than '../build' if you install from npm
+import * as fs from "fs";
+import { Document, Packer, Paragraph, TextRun } from "../build";
+
+const doc = new Document();
+
+doc.createParagraph("First Page").pageBreak();
+doc.createParagraph("Second Page");
+
+const pageNumber = new TextRun("Page ").pageNumber();
+
+const pageoneheader = new Paragraph("First Page Header ").right();
+
+pageoneheader.addRun(pageNumber);
+const firstPageHeader = doc.createFirstPageHeader();
+firstPageHeader.addParagraph(pageoneheader);
+
+const pagetwoheader = new Paragraph("My Title ").right();
+
+pagetwoheader.addRun(pageNumber);
+doc.Header.addParagraph(pagetwoheader);
+
+const packer = new Packer();
+
+packer.toBuffer(doc).then((buffer) => {
+    fs.writeFileSync("My Document.docx", buffer);
+});