Milestone 8 UX: folder tree workflows, about dialog, and app icon polish

src/about_dialog.h

@@ -0,0 +1,14 @@
+#ifndef ORBITHUB_ABOUT_DIALOG_H
+#define ORBITHUB_ABOUT_DIALOG_H
+
+#include <QDialog>
+
+class AboutDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit AboutDialog(QWidget* parent = nullptr);
+};
+
+#endif