~jaro/balkon

ref: ce4f4845a30de2bbcbce4c8c9eb2a0607b57588d 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.