Previews: beta docs (#47993)

* #44449: preview docs draft

* #44449: remove localhost

* #44449: fixes

* #44449: remove localhost

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

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* Update docs/sources/dashboards/previews.md

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* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

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* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

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* #44449: update link

* #44449: review comment https://github.com/grafana/grafana/pull/47993#discussion_r866363311

* #44449: https://github.com/grafana/grafana/pull/47993#discussion_r866363825

* #44449: https://github.com/grafana/grafana/pull/47993#discussion_r866364182

* #44449: https://github.com/grafana/grafana/pull/47993#discussion_r866365003

* #44449: https://github.com/grafana/grafana/pull/47993#discussion_r866359611

* #44449: https://github.com/grafana/grafana/pull/47993#discussion_r866361949

* #44449: add note about the first crawler run

* #44449: https://github.com/grafana/grafana/pull/47993/files#r866355629

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* fix up

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* typo

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/dashboards/previews.md

Co-authored-by: JitaC <70489351+achatterjee-grafana@users.noreply.github.com>

* rephrase

* replace gifs with webms

* reword

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docs/sources/administration/configuration.md

@@ -1921,3 +1921,27 @@ default_baselayer_config = `{
 ### enable_custom_baselayers
 
 Set this to `true` to disable loading other custom base maps and hide them in the Grafana UI. Default is `false`.
+
+## [dashboard_previews]
+
+### [crawler]
+
+> **Note:** This feature is available in Grafana v9.0 and later versions.
+
+#### thread_count
+
+Number of dashboards rendered in parallel. Default is 6
+
+#### rendering_timeout
+
+Timeout passed down to the Image Renderer plugin. It is used in two separate places within a single rendering request - during the initial navigation to the dashboard, and when waiting for all the panels to load. Default is 20s.
+
+#### max_crawl_duration
+
+Maximum duration of a single crawl. Default is 1h.
+
+#### scheduler_interval
+
+Minimum interval between two subsequent scheduler runs. Default is 12h.
+
+Refer to the [dashboards previews]({{< relref "../dashboards/previews.md" >}}) documentation for detailed instructions.