%embed addfield <embed name> <field name> ; <field value> [; inline(yes/no)]
Examples: %embed addfield sally Sally ; Cute chocolate lab ; yes
%embed addfield sally How old is Sally? ; 3 ; no
%embed addfield sally Sally is a ; chunky monkey
Aliases: createfield, newfield, af
Creates a new field in the embed with the given name and value, and inline status if it is provided.