Updating documentation links for exercises i_2, i_3, and i_4

src/i_introduction/_3_Default_Arguments/n03DefaultArguments.kt

@@ -1,7 +1,7 @@
 package i_introduction._3_Default_Arguments
 
 import util.TODO
-import util.doc2
+import util.doc3
 
 fun todoTask3(): Nothing = TODO(
     """
@@ -11,7 +11,7 @@ fun todoTask3(): Nothing = TODO(
         You have to add 'foo' parameters and implement its body.
         Uncomment the commented code and make it compile.
     """,
-    documentation = doc2(),
+    documentation = doc3(),
     references = { name: String -> JavaCode3().foo(name); foo(name) })
 
 fun foo(name: String): String = todoTask3()

src/util/LinksToDocumentation.kt

@@ -6,10 +6,14 @@ package util
 fun doc0() {}
 
 /**
- * @see <a href="https://kotlinlang.org/docs/reference/functions.html#default-arguments">Default and named arguments</a>
+ * @see <a href="https://kotlinlang.org/docs/reference/functions.html#named-arguments">Named arguments</a>
  */
 fun doc2() {}
 
+/**
+ * @see <a href="https://kotlinlang.org/docs/reference/functions.html#default-arguments">Default arguments</a>
+ */
+fun doc3() {}
 
 /**
  * @see <a href="https://kotlinlang.org/docs/reference/lambdas.html">Lambdas</a>