Add PDF writer.

src/publishing/pdf/PdfOutline.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "PdfObject.h"
+
+#include <vector>
+
+class PdfOutline : public PdfObject
+{
+public:
+    std::string ToString(PdfXRefTable* xRefTable) override;
+};
+using PdfOutlinePtr = std::unique_ptr<PdfOutline>;
+
+class PdfOutlineCollection : public PdfObject
+{
+public:
+
+    unsigned IndexObjects(unsigned count) override;
+
+    std::string ToString(PdfXRefTable* xRefTable) override;
+
+    void UpdateDictionary();
+
+private:
+    std::vector<PdfOutlinePtr> mOutlines;
+};