Doc:Replace cross doc links with attributes (logstash-plugins#985)

Fix inline reference
Rework description for inactivity option

* Doc: Clarify info about batch sizes
Co-authored-by: Ry Biesemeyer <[email protected]>

Bump to v.10.8.2

Author: karenzone

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 10.8.2
+ - [DOC] Update links to use shared attributes [#985](https://github.com/logstash-plugins/logstash-output-elasticsearch/pull/985)
+
 ## 10.8.1
  - Fixed an issue when assigning the no-op license checker [#984](https://github.com/logstash-plugins/logstash-output-elasticsearch/pull/984)