Minor javadoc fixes

Author: jhalterman

core/src/main/java/dev/failsafe/event/ExecutionCompletedEvent.java

@@ -18,7 +18,7 @@
 import dev.failsafe.ExecutionContext;
 
 /**
- * Indicates an execution was completed.
+ * Indicates an execution was completed or cancelled.
  *
  * @param <R> result type
  * @author Jonathan Halterman

core/src/main/java/dev/failsafe/event/ExecutionEvent.java

@@ -60,7 +60,7 @@ public int getExecutionCount() {
   }
 
   /**
-   * Returns the time that the initial execution started, else {code null} if an execution has not started yet.
+   * Returns the time that the initial execution started, else {@code null} if an execution has not started yet.
    */
   public Optional<Instant> getStartTime() {
     return Optional.ofNullable(context.getStartTime());