* gdk/tmpl/windows.sgml: Document GdkScreen.

	* gtk/gtk-sections.txt: Move a few Class structs to Standard sections.

	* gtk/tmpl/gtktreemodel.sgml, gtk/tmpl/gtkprogress.sgml,
	gtk/tmpl/gtksignal.sgml, gtk/tmpl/gtkimage.sgml: Generate proper
	markup for format strings in examples, also fix an oversight in
	the GtkTreeModel example.  (#74213)