type: string, default:
Controls how an image is positioned within its containing node.
imagepos only has an effect when the image is smaller than the containing node.
The default is to be centered both horizontally and vertically.
tl- Top Left
tc- Top Centered
tr- Top Right
ml- Middle Left
mc- Middle Centered (the default)
mr- Middle Right
bl- Bottom Left
bc- Bottom Centered
br- Bottom Right
Last modified June 14, 2021: Introduce per-attribute pages (81b00f5)