Document crm114 for logstash

Part of adding in crm114 queries to elastic-recheck.
Noting what crm114 is, why it is being used, how to use it
in kibana queries, and what file to patch to tweak it.
Related to Ie572ef90a3393b43d28608b95a8a9b24bd014962,
the elastic-recheck crm114 patch.

Change-Id: I086b2dfa68ca2239d70cec6db0b22951e6786ed7
Merge "Document crm114 for logstash"