Update Elasticsearch dependency management and add documentation.
Review Request #11892 — Created Dec. 15, 2021 and submitted
Review Board no longer depends on the
we now provide
ReviewBoard[elasticsearchX]packages for each supported
major version of Elasticsearch.
The instructions on the settings page reference these dependencies,
easing installation a bit, especially if we need to bump or cap versions
down the road.
Documentation has been updated to list the installation requirements,
and to list these packages.
Tested installing the dependency wrapper packages.
Verified the text on the configuration page and in the documentation.