Update users_comments.md

Author: AtsushiSakai

users_comments.md

@@ -3,7 +3,7 @@
 
 This is a list of users who are using PythonRobotics for education.
 
-If you found other users, please make an issue and let me know.
+If you found other users, please make an issue to let me know.
 
 - [CSCI/ARTI 4530/6530: Introduction to Robotics (Fall 2018),  University of Georgia ](http://cobweb.cs.uga.edu/~ramviyas/csci_x530.html)