Improve macro documentation.
Improve macro documentation.

AlecZorab/spire,rklaehn/spire,non/spire,codeaudit/spire,kevinmeredith/spire,non/spire,tixxit/spire,codeaudit/spire,adampingel/spire,kevinmeredith/spire,AlecZorab/spire,rklaehn/spire,siddhartha-gadgil/spire,guersam/spire,tixxit/spire,siddhartha-gadgil/spire,adampingel/spire,JackSullivan/spire,guersam/spire,woparry/spire,woparry/spire,JackSullivan/spire