Added/updated snippets for docs (#2318)

docs/doc_examples/49b31e23f8b9667b6a7b2734d55fb6ed.asciidoc

@@ -0,0 +1,17 @@
+// 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.knnSearch({
+  index: "my-index",
+  knn: {
+    field: "image_vector",
+    query_vector: [0.3, 0.1, 1.2],
+    k: 10,
+    num_candidates: 100,
+  },
+  _source: ["name", "file_type"],
+});
+console.log(response);
+----