Add flag to turn power assertions on/off (#1419)

docs/modules/pkl-gradle/pages/index.adoc

@@ -322,6 +322,16 @@ Default: `false` +
 Whether to ignore expected example files and generate them again.
 ====
 
+[[power-assertions-test]]
+.powerAssertions: Property<Boolean>
+[%collapsible]
+====
+Default: `true` (for test tasks) +
+Example: `powerAssertions = false` +
+Enable or disable power assertions for detailed assertion failure messages.
+When enabled, test failures will show intermediate values in the assertion expression, making it easier to understand why a test failed.
+====
+
 Common properties:
 
 include::../partials/gradle-modules-properties.adoc[]