[DOCS] Remove snapshot and restore docs (#114836) (#118810)

With elastic/elasticsearch#79081, we now cover Kibana's **Snapshot and Restore** feature in the Elasticsearch docs. This removes and redirects the related docs from Kibana.

It also updates some references to the `.kibana` system indices to include the `kibana` feature state. The `kibana` feature state is now the preferred way to back up and restore system indices and other configuration data for Kibana.

Relates to elastic/elasticsearch#79675
# Conflicts:
#	docs/setup/upgrade.asciidoc
#	docs/template.asciidoc

docs/redirects.asciidoc

@@ -7,6 +7,14 @@
 The following pages have moved or been deleted.
 
 --
+[role="exclude",id="snapshot-repositories"]
+== Snapshot and Restore
+Refer to {ref}/snapshot-restore.html[Snapshot and Restore].
+
+[role="exclude",id="snapshot-restore-tutorial"]
+== Tutorial: Snapshot and Restore
+Refer to {ref}/snapshot-restore.html[Snapshot and Restore].
+
 [role="exclude",id="configuring-tls"]
 == Encrypt TLS communications in {kib}
 Refer to {ref}/security-basic-setup-https.html#encrypt-kibana-http[Encrypt HTTP client communications for {kib}].

docs/setup/upgrade.asciidoc

@@ -58,12 +58,12 @@ The upgrade path from 6.8 to 7.0 is *not* supported.
 [[upgrade-before-you-begin]]
 === Before you begin
 
-WARNING: {kib} automatically runs upgrade migrations when required. To roll back to an earlier version in case of an upgrade failure, you **must** have a backup snapshot available. Use <<snapshot-repositories, Snapshot and Restore>> to back up {kib} data by targeting the `.kibana*` indices. For more information see <<upgrade-migrations, upgrade migrations>>.
+WARNING: {kib} automatically runs upgrade migrations when required. To roll back to an earlier version in case of an upgrade failure, you **must** have a {ref}/snapshot-restore.html[backup snapshot] available. This snapshot must include the `kibana` feature state or all `kibana*` indices. For more information see <<upgrade-migrations, upgrade migrations>>.
 
 Before you upgrade {kib}:
 
 * Consult the <<release-notes,breaking changes>>.
-* Back up your data with <<snapshot-repositories, Snapshot and Restore>>. To roll back to an earlier version, you **must** have a snapshot of the `.kibana*` indices. 
+* {ref}/snapshots-take-snapshot.html[Take a snapshot] of your data. To roll back to an earlier version, the snapshot must include the `kibana` feature state or all `.kibana*` indices. 
 * Although not a requirement for rollbacks, we recommend taking a snapshot of all {kib} indices created by the plugins you use such as the `.reporting*` indices created by the reporting plugin.  
 * Before you upgrade production servers, test the upgrades in a dev environment.
 * See <<preventing-migration-failures, preventing migration failures>> for common reasons upgrades fail and how to prevent these.

docs/setup/upgrade/upgrade-migrations.asciidoc

@@ -151,17 +151,17 @@ In order to rollback after a failed upgrade migration, the saved object indices
 [float]
 ===== Rollback by restoring a backup snapshot:
 
-1. Before proceeding ensure that you have a recent and successful backup snapshot of all `.kibana*` indices.
+1. Before proceeding, {ref}/snapshots-take-snapshot.html[take a snapshot] that contains the `kibana` feature state or all `.kibana*` indices.
 2. Shutdown all {kib} instances to be 100% sure that there are no instances currently performing a migration.
 3. Delete all saved object indices with `DELETE /.kibana*`
-4. Restore the `.kibana* indices and their aliases from the backup snapshot. See {es} {ref}/modules-snapshots.html[snapshots]
+4. {ref}/snapshots-restore-snapshot.html[Restore] the `kibana` feature state or all `.kibana* indices and their aliases from the snapshot.
 5. Start up all {kib} instances on the older version you wish to rollback to.
 
 [float]
 ===== (Not recommended) Rollback without a backup snapshot:
 
 1. Shutdown all {kib} instances to be 100% sure that there are no {kib} instances currently performing a migration.
-2. Create a backup snapshot of the `.kibana*` indices.
+2. {ref}/snapshots-take-snapshot.html[Take a snapshot] that includes the `kibana` feature state or all `.kibana*` indices.
 3. Delete the version specific indices created by the failed upgrade migration. E.g. if you wish to rollback from a failed upgrade to v7.12.0 `DELETE /.kibana_7.12.0_*,.kibana_task_manager_7.12.0_*`
 4. Inspect the output of `GET /_cat/aliases`. If either the `.kibana` and/or `.kibana_task_manager` alias is missing, these will have to be created manually. Find the latest index from the output of `GET /_cat/indices` and create the missing alias to point to the latest index. E.g. if the `.kibana` alias was missing and the latest index is `.kibana_3` create a new alias with `POST /.kibana_3/_aliases/.kibana`.
 5. Remove the write block from the rollback indices. `PUT /.kibana,.kibana_task_manager/_settings {"index.blocks.write": false}`

docs/user/management.asciidoc

@@ -45,7 +45,7 @@ through the hot, warm, cold, and delete phases.
 Such policies help you control operation costs
 because you can put data in different resource tiers.
 
-| <<snapshot-repositories, Snapshot and Restore>>
+| {ref}/snapshot-restore.html[Snapshot and Restore]
 |Define a policy that creates, schedules, and automatically deletes snapshots to ensure that you
 have backups of your cluster in case something goes wrong.
 
@@ -193,8 +193,6 @@ include::{kib-repo-dir}/management/managing-saved-objects.asciidoc[]
 
 include::security/index.asciidoc[]
 
-include::{kib-repo-dir}/management/snapshot-restore/index.asciidoc[]
-
 include::{kib-repo-dir}/spaces/index.asciidoc[]
 
 include::{kib-repo-dir}/management/managing-tags.asciidoc[]

src/core/public/doc_links/doc_links_service.ts

@@ -427,7 +427,7 @@ export class DocLinksService {
           snapshotRestoreRepos: `${PLUGIN_DOCS}repository.html`,
         },
         snapshotRestore: {
-          guide: `${KIBANA_DOCS}snapshot-repositories.html`,
+          guide: `${ELASTICSEARCH_DOCS}snapshot-restore.html`,
           changeIndexSettings: `${ELASTICSEARCH_DOCS}index-modules.html`,
           createSnapshot: `${ELASTICSEARCH_DOCS}snapshots-take-snapshot.html`,
           getSnapshot: `${ELASTICSEARCH_DOCS}get-snapshot-api.html`,