doc: add GraalJS shield

Author: ChALkeR

README.md

@@ -33,6 +33,7 @@ Tested in CI with [@exodus/test](https://github.com/ExodusMovement/test#exoduste
 [![SpiderMonkey](https://img.shields.io/badge/SpiderMonkey-FFD681?style=for-the-badge)](https://spidermonkey.dev/)
 [![QuickJS](https://img.shields.io/badge/QuickJS-E58200?style=for-the-badge)](https://github.com/quickjs-ng/quickjs)
 [![XS](https://img.shields.io/badge/XS-0B307A?style=for-the-badge)](https://github.com/Moddable-OpenSource/moddable)
+[![GraalJS](https://img.shields.io/badge/GraalJS-C74634?style=for-the-badge)](https://github.com/oracle/graaljs)
 
 ## Fast