Doc generator: avoid empty 'Implements' sections
Doc generator: avoid empty 'Implements' sections

GuillaumeGomez/gir,EPashkin/gir,gtk-rs/gir,GuillaumeGomez/gir,gkoz/gir,gkoz/gir,gtk-rs/gir,GuillaumeGomez/gir,EPashkin/gir,gtk-rs/gir