~jaro/balkon

ref: 03d36342529a318aa40fa9da94e8555e2f2017d5 balkon/lib/Data/Text/ParagraphLayout/Plain.hs -rw-r--r-- 1.7 KiB 
Deprecate the Plain interface.

Add user data to spans.

Add line numbers to laid out fragments.

Qualify Plain interface.