Update CSS to include spacing after tables

[jtravee]

Could we update the CSS such that the next line/paragraph does not fall right under it? I attached a pic from my local build after entering a line of text beneath a table. As it is now, I manually add a line break in there when needed to fix this, and that tends to look ugly and also can cause the preview in the Github MD files to not render right (often) for the reviewer.

Ideally, there should be at least one line of spacing built in after the table.