update README

Author: mbchang

README.md

@@ -170,7 +170,7 @@ This project was built with [Torch7](http://torch.ch),
 [matter-js](http://brm.io/matter-js/). A big thank you to these folks.
 
 We thank Tejas Kulkarni for insightful discussions and guidance. We thank Ilker
-Yidirim, Erin Reynolds, Feras Saad, Andreas Stuhlmuller, Adam Lerer, Chelsea
+Yildirim, Erin Reynolds, Feras Saad, Andreas Stuhlmuller, Adam Lerer, Chelsea
 Finn, Jiajun Wu, and the anonymous reviewers for valuable feedback. We thank
 Liam Brummit, Kevin Kwok, and Guillermo Webster for help with matter-js. M.
 Chang was graciously supported by MIT’s SuperUROP and UROP programs.