minor correction

docs/index.md

@@ -21,8 +21,8 @@ affiliations:
 ## Abstract
 Legged locomotion is arguably the most suited and
 versatile mode to deal with natural or unstructured terrains.
-Intensive research into dynamic walking and running con-
-trollers has recently yielded great advances, both in the optimal
+Intensive research into dynamic walking and running controllers
+has recently yielded great advances, both in the optimal
 control and reinforcement learning (RL) literature. Hopping is
 a challenging dynamic task involving a flight phase and has
 the potential to increase the traversability of legged robots.