Merge branch 'docs-mgibsongl-standardize-reindex-elasticsearch' into 'master'

Standardize spelling of reindex on Elasticsearch Docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/184509



Merged-by: Ashraf Khamis <akhamis@gitlab.com>
Co-authored-by: Michael Gibson <mgibson@gitlab.com>