[DOCS] Document missing script APIs (#72175)

Documents the following APIs:

* [Delete stored script][0]
* [Get stored script][1]
* [Get script contexts][2]
* [Get script languages][3]

[0]: https://github.com/elastic/elasticsearch/blob/master/rest-api-spec/src/main/resources/rest-api-spec/api/delete_script.json
[1]: https://github.com/elastic/elasticsearch/blob/master/rest-api-spec/src/main/resources/rest-api-spec/api/get_script.json
[2]: https://github.com/elastic/elasticsearch/blob/master/rest-api-spec/src/main/resources/rest-api-spec/api/get_script_context.json
[3]: https://github.com/elastic/elasticsearch/blob/master/rest-api-spec/src/main/resources/rest-api-spec/api/get_script_languages.json

docs/reference/scripting/apis/delete-stored-script-api.asciidoc

@@ -0,0 +1,48 @@
+[[delete-stored-script-api]]
+=== Delete stored script API
+++++
+<titleabbrev>Delete stored script</titleabbrev>
+++++
+
+Deletes a <<script-stored-scripts,stored script>> or <<search-template,search
+template>>.
+
+////
+[source,console]
+----
+PUT _scripts/my-stored-script
+{
+  "script": {
+    "lang": "painless",
+    "source": """
+      TimestampHour date =  doc['@timestamp'].value; 
+      return date.getHour()
+    """
+  }
+}
+----
+////
+
+[source,console]
+----
+DELETE _scripts/my-stored-script
+----
+// TEST[continued]
+
+[[delete-stored-script-api-prereqs]]
+==== {api-prereq-title}
+
+* If the {es} {security-features} are enabled, you must have the `manage`
+<<privileges-list-cluster,cluster privilege>> to use this API.
+
+[[delete-stored-script-api-path-params]]
+==== {api-path-parms-title}
+
+`<script-id>`::
+(Required, string)
+Identifier for the stored script or search template.
+
+[[delete-stored-script-api-query-params]]
+==== {api-query-parms-title}
+
+include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=timeoutparms]