Unify kotlin.test docs

libraries/kotlin.test/common/src/main/kotlin/kotlin/test/AssertionsH.kt

@@ -8,8 +8,9 @@ package kotlin.test
 import kotlin.reflect.KClass
 
 /**
- * Comments out a block of test code until it is implemented while keeping a link to the code
- * to implement in your unit test output
+ * Takes the given [block] of test code and _doesn't_ execute it.
+ *
+ * This keeps the code under test referenced, but doesn't actually test it until it is implemented.
  */
 expect fun todo(block: () -> Unit)