Clarified context role in the examples

example_test.go

@@ -19,7 +19,7 @@ import (
 
 // This example demonstrates a Rill pipeline that fetches users from an API,
 // updates their status to active and saves them back.
-// Both operations are performed concurrently
+// Both operations are performed concurrently.
 // [ForEach] returns on the first error, and context cancellation via defer stops all remaining fetches.
 func Example() {
 	ctx, cancel := context.WithCancel(context.Background())