the headline string will be used to annotate itemized lists of cross references to the documentation Key
Description
The headline of a documentation node, gives a brief, half line, description of the thing being documented. As an example, the headline for this documentation node was obtained with the code:
Headline => "make a headline for a documentation node",
Functions with optional argument named Headline :
document(..., Headline => ...)
newPackage(..., Headline => ...), see newPackage(String) -- package item: start a new package