[comp-scroll-anim] Markdown formatting fix.

Author: ianvollick

composited-scrolling-and-animation/UseCases.md

@@ -25,6 +25,7 @@ Gesture Recognition
 - With the ability to process input on the compositor thread, we would have the ability to write custom gesture recognition.
 
 Location Tracking
+----
 - It would be nice to keep track of the location of an element with respect to another element (in particular, a scroll clip), to get an asynchronous, as-accurate-as-possible set of records of the element's location history.