~jaro/balkon

ref: 1e8de66a311429538c26baf8e8a6fac212270e42 balkon/src/Data/Text/ParagraphLayout/Internal/ParagraphExtents.hs -rw-r--r-- 925 bytes 
Allow paragraphRect without point 0,0.

Parametrise rectangle union bias.

Separate interface-independent constants.