Add Star History section to README

Author: OmidS

README.md

@@ -143,3 +143,6 @@ Copyright (c) 2020 University of Southern California
 See full notice in [LICENSE.md](https://github.com/ShanechiLab/PyPSID/blob/main/LICENSE.md)  
 Omid G. Sani, Parsa Vahidi and Maryam M. Shanechi  
 Shanechi Lab, University of Southern California
+
+# Star History
+[![Star History Chart](https://api.star-history.com/svg?repos=ShanechiLab/PyPSID&type=Date)](https://star-history.com/#ShanechiLab/PyPSID&Date)