[DOCS] Add delete snapshot repo API docs (#57043)

Changes:

* Adds API reference docs for the delete snapshot repo API.

* Corrects an error in the delete snapshot repo API spec. Comma-separated
repository names are not supported.

* Relocates the existing delete snapshot repo API example docs.

docs/reference/snapshot-restore/apis/delete-repo-api.asciidoc

@@ -0,0 +1,56 @@
+[[delete-snapshot-repo-api]]
+=== Delete snapshot repository API
+++++
+<titleabbrev>Delete snapshot repository</titleabbrev>
+++++
+
+Unregisters one or more <<snapshots-register-repository,snapshot repositories>>.
+
+When a repository is unregistered, {es} only removes the reference to the
+location where the repository is storing the snapshots. The snapshots themselves
+are left untouched and in place.
+
+////
+[source,console]
+----
+PUT /_snapshot/my_repository
+{
+  "type": "fs",
+  "settings": {
+    "location": "my_backup_location"
+  }
+}
+----
+////
+
+[source,console]
+----
+DELETE /_snapshot/my_repository
+----
+// TEST[continued]
+
+[[delete-snapshot-repo-api-request]]
+==== {api-request-title}
+
+`DELETE /_snapshot/<repository>`
+
+[[delete-snapshot-repo-api-path-params]]
+==== {api-path-parms-title}
+
+`<repository>`::
+(Required, string)
+Name of the snapshot repository to unregister. Wildcard (`*`) patterns are
+supported.
+
+[[delete-snapshot-repo-api-query-params]]
+==== {api-query-parms-title}
+
+`master_timeout`::
+(Optional, <<time-units, time units>>) Specifies the period of time to wait for
+a connection to the master node. If no response is received before the timeout
+expires, the request fails and returns an error. Defaults to `30s`.
+
+`timeout`::
+(Optional, <<time-units, time units>>) Specifies the period of time to wait for
+a response. If no response is received before the timeout expires, the request
+fails and returns an error. Defaults to `30s`.

docs/reference/snapshot-restore/apis/snapshot-restore-apis.asciidoc

@@ -17,8 +17,10 @@ content may not be included yet.
 === Snapshot repository management APIs
 
 * <<clean-up-snapshot-repo-api,Clean up snapshot repository>>
+* <<delete-snapshot-repo-api,Delete snapshot repository>>
 * <<put-snapshot-repo-api,Put snapshot repository>>
 
 
 include::clean-up-repo-api.asciidoc[]
+include::delete-repo-api.asciidoc[]
 include::put-repo-api.asciidoc[]

docs/reference/snapshot-restore/register-repository.asciidoc

@@ -79,6 +79,18 @@ or
 GET /_snapshot/_all
 -----------------------------------
 
+You can unregister a repository using the <<delete-snapshot-repo-api,delete
+snapshot repository API>>:
+
+[source,console]
+-----------------------------------
+DELETE /_snapshot/my_backup
+-----------------------------------
+
+When a repository is unregistered, {es} only removes the reference to the
+location where the repository is storing the snapshots. The snapshots themselves
+are left untouched and in place.
+
 [float]
 [[snapshots-filesystem-repository]]
 === Shared file system repository

docs/reference/snapshot-restore/take-snapshot.asciidoc

@@ -192,16 +192,3 @@ snapshot and not used by any other snapshots. If the deleted snapshot operation
 created the snapshotting process will be aborted and all files created as part of the snapshotting process will be
 cleaned. Therefore, the delete snapshot operation can be used to cancel long running snapshot operations that were
 started by mistake.
-
-A repository can be unregistered using the following command:
-
-[source,console]
------------------------------------
-DELETE /_snapshot/my_backup
------------------------------------
-// TEST[continued]
-
-When a repository is unregistered, Elasticsearch only removes the reference to the location where the repository is storing
-the snapshots. The snapshots themselves are left untouched and in place.
-
-

rest-api-spec/src/main/resources/rest-api-spec/api/snapshot.delete_repository.json

@@ -15,7 +15,7 @@
           "parts":{
             "repository":{
               "type":"list",
-              "description":"A comma-separated list of repository names"
+              "description":"Name of the snapshot repository to unregister. Wildcard (`*`) patterns are supported."
             }
           }
         }