docs: update readme

Author: nattb8

README.md

@@ -14,8 +14,7 @@ The Immutable SDK for Unity helps you integrate your game with Immutable Passpor
 
 # Documentation
 
-* [Immutable X](https://docs.immutable.com/reference/unity/)
-* [Immutable zkEVM](https://docs.immutable.com/reference/unity/)
+For setup instructions and API references, see the [official documentation](https://docs.immutable.com/reference/unity/).
 
 ## Sample Projects