Rearrange docs (#64566)

Rearrange docs (#64566)

        * gtk/gtkbutton.c (gtk_button_get_label): Rearrange docs (#64566)

        * gtk/gtktextbuffer.c (gtk_text_buffer_create_tag): Typo fix (#64474)

        * gtk/gtkruler.c (gtk_ruler_get_metric): Typo fix (#64470)

        * gtk/gtknotebook.c (gtk_notebook_prepend_page): Typo fix (#64467)

        * gtk/gtklabel.c: Documentation fixes (#64452)

        * docs/reference/gdk/Makefile.am (MKDB_OPTIONS),
        docs/reference/gdk-pixbuf/Makefile.am (MKDB_OPTIONS),
        docs/reference/gtk/Makefile.am (MKDB_OPTIONS): Add --sgml-mode.

        * docs/reference/gdk-pixbuf/tmpl/file-saving.sgml,
        docs/reference/gdk-pixbuf/tmpl/module_interface.sgml,
        docs/reference/gdk-pixbuf/tmpl/gdk-pixbuf-xlib-rgb.sgml: Consistent short descriptions.
        * docs/reference/gtk/tmpl/gtkprogressbar.sgml: Remove duplicate docs. (#64469)

        * docs/reference/gtk/gtk-sections.txt: Add missing TITLEs (#64459, #6456