LibMarkdown: Implement "tightness" for lists

From the commonmark spec:
A list is loose if any of its constituent list items are separated by
blank lines, or if any of its constituent list items directly contain
two block-level elements with a blank line between them. Otherwise a
list is tight. (The difference in HTML output is that paragraphs in a
loose list are wrapped in <p> tags, while paragraphs in a tight list are
not.)

Userland/Libraries/LibMarkdown/Table.cpp

@@ -65,7 +65,7 @@ String Table::render_for_terminal(size_t view_width) const
     return builder.to_string();
 }
 
-String Table::render_to_html() const
+String Table::render_to_html(bool) const
 {
     StringBuilder builder;