[forwardlist.modifiers] Properly indent Returns: paragraph.

Closes #200.

Author: sdutoit

source/containers.tex

@@ -3839,10 +3839,10 @@
 \pnum
 \effects Inserts an object of type \tcode{value_type} constructed with
 \tcode{value_type(std::forward<Args>(\brk{}args)...)} after \tcode{position}.
-\end{itemdescr}
 
 \pnum
 \returns An iterator pointing to the new object.
+\end{itemdescr}
 
 \indexlibrary{\idxcode{erase_after}!\idxcode{forward_list}}%
 \indexlibrary{\idxcode{forward_list}!\idxcode{erase_after}}%