improve the docs on in-flight jobs of killed/lost workers (#1840)

* improve the docs on in-flight jobs of killed/lost workers

* improve the docs on in-flight jobs of killed/lost workers

* document abandoned job behavior before 0.14

docs/docs/results.md

@@ -78,10 +78,12 @@ chance to finish themselves.
 However, workers can be killed forcefully by `kill -9`, which will not give the
 workers a chance to finish the job gracefully or to put the job on the `failed`
 queue.  Therefore, killing a worker forcefully could potentially lead to
-damage.
-
-Just sayin'.
+damage. Just sayin'.
 
+If the worker gets killed while a job is running, it will eventually end up in
+`FailedJobRegistry` because a cleanup task will raise an `AbandonedJobError`.
+Before 0.14 the behavor was the same, but the cleanup task raised a
+`Moved to FailedJobRegistry at` error message instead.
 
 ## Dealing with Job Timeouts