add new line after list

otherwise, during the html conversion the ul and li tags are not placed where
they need to go.

motivation.html

@@ -26,6 +26,7 @@
 <section class="slide">
 <h2 id="why-topic">Why Topic?</h2>
 </section>
+
 <section class="slide">
 <h2 id="more-explanation">More Explanation</h2>
 <ul>
@@ -34,6 +35,7 @@
 <li>Points</li>
 </ul>
 </section>
+
 <section class="slide">
 <h2 id="next-steps">Next Steps</h2>
 Here we go!

motivation.md

@@ -13,6 +13,7 @@ subtitle: Motivation
 * With
 * Bullet
 * Points
+
 </section>
 
 <section class="slide">