Remove margin-bottom for list items

[ulinaaron]

This is an oversight that just needs to be removed from the next build. Currently all list items have a bottom margin. If anything they just need natural line spacing going forward.

tentcss/src/04_elements/_lists.scss

Line 21 in b563e72

margin-bottom: map-get($spaces, xxxs);

 margin-bottom: map-get($spaces, xxxs);