Fix link

Author: FujiHaruka

README.md

@@ -124,6 +124,6 @@ To view all available built-in aliases, simply use the `LIST` command:
 > LIST
 ```
 
-For more examples, feel free to explore [fixtures/](./fixtures/). These built-in
+For more examples, feel free to explore [fixtures/](https://github.com/FujiHaruka/lambda-calculus/tree/main/fixtures). These built-in
 aliases not only make common lambda calculus operations more convenient but also
 allow you to focus on more complex concepts and computations.