Issue #3248976: Add API documentation for Package Manager

package_manager/package_manager.api.php

@@ -42,8 +42,8 @@
  * helpful to ensure that the staging area is in a valid state. Post-operation
  * events are simple triggers allowing custom code to react when an operation
  * is complete. They cannot flag errors that block the stage life cycle from
- * continuing, although they can use the core messenger and logging systems to
- * log errors.
+ * continuing, although they can use the core messenger and logging systems as
+ * needed.
  *
  * All stage events extend \Drupal\package_manager\Event\StageEvent, and all
  * pre-operation events extend
@@ -88,8 +88,8 @@
  *
  * - \Drupal\package_manager\Event\PreDestroyEvent
  *   Dispatched before the staging area is destroyed, during which the temporary
- *   directory will be completely deleted the stage will release its ownership.
- *   Only dispatched once during a stage's life cycle.
+ *   directory will be completely deleted and the stage will release its
+ *   ownership. Only dispatched once during a stage's life cycle.
  *
  * - \Drupal\package_manager\Event\PostDestroy
  *   Dispatched after the staging area is destroyed and the stage has released