Updating index

Author: feliun

README.md

@@ -3,6 +3,8 @@ Here you will find some different code challenges options for interviewing at Gu
 
 ## Node tests
 [Implement the martian robots game](/node/martian-robots/instructions.md)
+[Implement the tennis score game](/node/tennis-score/instructions.md)
 
 ## React code tests
 [Build a phone catalogue](/react/phone-catalogue/instructions.md)
+[Build an app around a misteriuos API](/react/misterious-api/instructions.md)