changed readme

Author: drblallo

README.md

@@ -6,6 +6,7 @@ The Rulebook language lets you write complex interactive systems with the simpli
 
 
 [Paper for Reinforcement Learning users](https://arxiv.org/abs/2504.19625)
+
 See Rulebook in action [repo](https://github.com/rl-language/4Hammer) [paper](https://arxiv.org/abs/2505.13638) [doc](https://rl-language.github.io/4hammer.html)
 
 ### Contacts