Previews: update docs for the new search layout (#50130)
Previews: update docs for the new search layout (#50130)

* #44449: update docs, remove the mention of `Show previews` toggle

* #44449: remove formatting of `grid`

* #44449: review

* review https://github.com/grafana/grafana/pull/50130#discussion_r888449621
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana