Add docs for the batch mode of plugin installation (#21700)
Add docs for the batch mode of plugin installation (#21700)

* Add docs for the batch mode of plugin installation

Closes https://github.com/elastic/elasticsearch/issues/21490

* Updated to clarify that all permissions are granted automatically in batch mode

strapdata/elassandra5-rc,strapdata/elassandra5-rc,strapdata/elassandra5-rc,strapdata/elassandra5-rc,strapdata/elassandra5-rc