Update README.md

Author: gcasa

README.md

@@ -65,3 +65,13 @@ information in the Documentation directory of this project.
 are permitted in any medium without royalty provided the copyright
 notice and this notice are preserved.
 
+## Star History
+
+<a href="https://www.star-history.com/#gnustep/libs-xcode&Date">
+ <picture>
+   <source media="(prefers-color-scheme: dark)" srcset="https://api.star-history.com/svg?repos=gnustep/libs-xcode&type=Date&theme=dark" />
+   <source media="(prefers-color-scheme: light)" srcset="https://api.star-history.com/svg?repos=gnustep/libs-xcode&type=Date" />
+   <img alt="Star History Chart" src="https://api.star-history.com/svg?repos=gnustep/libs-xcode&type=Date" />
+ </picture>
+</a>
+