Previously, cross-cluster replication (CCR) documentation was located in
the Stack Overview:
https://www.elastic.co/guide/en/elastic-stack-overview/master/xpack-ccr.html
This adds CCR documentation to the Elasticsearch Reference Guide with a
level offset for headings.
The level offset and CCR Stack Overview docs will be removed in later
commits.
This commit expands the ccr overview page to include more information
about the lifecycle of following an index. It adds information linking
to the remote recovery documentation. And describes how an index can
fall-behind and how to fix it when this happens.
* Add guidance on using CCR with Logstash
This commit adds a note to the documentation regarding how to configure
Logstash indices in the context of being available as leader indices for
cross-cluster replication.
* Oh okay
* idk
* notconsole
James Rodewig
Tim Brooks
Lisa Cawley
Jason Tedor
Nhat Nguyen