[Backport 8.15] Added/updated snippets for docs (#2319)

(cherry picked from commit f737290d10)

Co-authored-by: Josh Mock <joshua.mock@elastic.co>

docs/doc_examples/0f4583c56cfe5bd59eeb35bfba02957c.asciidoc

@@ -0,0 +1,27 @@
+// This file is autogenerated, DO NOT EDIT
+// Use `node scripts/generate-docs-examples.js` to generate the docs examples
+
+[source, js]
+----
+const response = await client.rankEval({
+  index: "my-index-000001",
+  requests: [
+    {
+      id: "JFK query",
+      request: {
+        query: {
+          match_all: {},
+        },
+      },
+      ratings: [],
+    },
+  ],
+  metric: {
+    recall: {
+      k: 20,
+      relevant_rating_threshold: 1,
+    },
+  },
+});
+console.log(response);
+----