Fix broken link

Author: liufengyun

docs/docs/reference/other-new-features/explicit-nulls.md

@@ -46,7 +46,7 @@ val c = new C()
 ```
 
 The unsoundness above can be caught by the compiler with the option `-Ycheck-init`.
-More details can be found in [safe initialization](./safe-initializaion.md).
+More details can be found in [safe initialization](./safe-initialization.md).
 
 ## Equality