Advanced Search: Add meta field to indices mappings
For debugging purposes it would be extremely helpful to have additional information for every index. I believe we should add the version of GitLab that created the index in this field as our first iteration.
We could also output this information in #340437 (closed)
https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-meta-field.html
Edited by Dmitry Gruzd