docs: Add an explicit example of image loading
docs: Add an explicit example of image loading

Using GdkPixbuf, which is what we expect people to use anyway.

ebassi/clutter,jigpu/clutter,jigpu/clutter,jigpu/clutter,djdeath/clutter,GNOME/clutter,djdeath/clutter,djdeath/clutter,Distrotech/clutter,ebassi/clutter,Distrotech/clutter,GNOME/clutter,GNOME/clutter,GNOME/clutter,GNOME/clutter,Distrotech/clutter,ebassi/clutter,djdeath/clutter,Distrotech/clutter,djdeath/clutter,jigpu/clutter,jigpu/clutter,jigpu/clutter,ebassi/clutter,djdeath/clutter,Distrotech/clutter,ebassi/clutter,Distrotech/clutter