[Docs] Improve Redindex/Update/Delete By Query. (#35127)

Fix a copy paste error and improve formatting in
Redindex/Update/Delete By Query and fix formula in Update By Query.

docs/reference/docs/delete-by-query.asciidoc

@@ -277,7 +277,7 @@ The number of requests per second effectively executed during the delete by quer
 
 `throttled_until_millis`::
 
-This field should always be equal to zero in a delete by query response. It only
+This field should always be equal to zero in a `_delete_by_query` response. It only
 has meaning when using the <<docs-delete-by-query-task-api, Task API>>, where it
 indicates the next time (in milliseconds since epoch) a throttled request will be
 executed again in order to conform to `requests_per_second`.

docs/reference/docs/reindex.asciidoc

@@ -671,7 +671,7 @@ The number of requests per second effectively executed during the reindex.
 
 `throttled_until_millis`::
 
-This field should always be equal to zero in a `_delete_by_query` response. It only
+This field should always be equal to zero in a `_reindex` response. It only
 has meaning when using the <<docs-reindex-task-api, Task API>>, where it
 indicates the next time (in milliseconds since epoch) a throttled request will be
 executed again in order to conform to `requests_per_second`.

docs/reference/docs/update-by-query.asciidoc

@@ -237,7 +237,7 @@ batch size is `1000`, so if the `requests_per_second` is set to `500`:
 [source,txt]
 --------------------------------------------------
 target_time = 1000 / 500 per second = 2 seconds
-wait_time = target_time - delete_time = 2 seconds - .5 seconds = 1.5 seconds
+wait_time = target_time - write_time = 2 seconds - .5 seconds = 1.5 seconds
 --------------------------------------------------
 
 Since the batch is issued as a single `_bulk` request large batch sizes will
@@ -332,7 +332,7 @@ The number of requests per second effectively executed during the update by quer
 
 `throttled_until_millis`::
 
-This field should always be equal to zero in a delete by query response. It only
+This field should always be equal to zero in an `_update_by_query` response. It only
 has meaning when using the <<docs-update-by-query-task-api, Task API>>, where it
 indicates the next time (in milliseconds since epoch) a throttled request will be
 executed again in order to conform to `requests_per_second`.