add pre-output check to exercise

Author: figaw

skipping-execution/README.md

@@ -4,10 +4,14 @@ This exercise's `build.gradle` contains a task called `dangerousTask`.
 The project keeps track of a `riskLevel`, which increases when you run `dangerousTask`.
 Our reactor will overload and explode if `riskLevel` grows higher than 100.
 
-Modify `dangerousTask` to prevent it from executing if `riskLevel` could potentially increase past 100.
-However, do so without modifying existing lines of code.
-
 - Run `./gradlew dangerousTask` until you reach critical risk levels
-- Run `./gradlew dangerousTask` once more, for science
+- Run `./gradlew dangerousTask` once more (for science!)
 - Q: Did your reactor overload? If so, what went wrong?
+- Overwrite the value in the `risk.txt` file to `60`.
+
+Modify `dangerousTask` to prevent it from executing if `riskLevel` could potentially increase past 100.
+However, do so without modifying anything in the `doLast`-block.
+
+- Run `./gradlew dangerousTask` and watch your `riskLevel` rise
+- Q: Is your reactor still overloading?
 - Q: What are the differences between `onlyIf`, `return`, `StopExecutionException`, `./gradlewException`? When would you use them?