orderby parameter for the jetpack_portfolio shortcode

Syntax

[jetpack_portfolio
display_types="true| false - Display Project Types"
display_tags="true| false - Display Project Tags"
display_content="true| false - Display Project Content"
show_filter="false| true - Display a filter"
include_type="| type1,type2 - Comma separated list of Project Type slugs to include"
include_tag="| tag1,tag2 - Comma separated list of Project Tag slugs to include"
columns="2| numeric - Number of columns, between 1 and 6"
showposts="-1| numeric - Number of posts to show -1=all"
order="ASC| DESC - Display projects in ascending or descending order"
orderby="date| author| title| rand - Sort projects by different criteria"]