DOCSP-32718: listindexes code comments (#767)

Author: rustagir

source/code-snippets/indexes/listIndexes.js

@@ -1,27 +1,33 @@
+// List indexes
+
 const { MongoClient } = require("mongodb");
 
-// Replace the following with your MongoDB deployment's connection
-// string.
+// Replace the placeholders with your credentials
 const uri =
   "mongodb+srv://<user>:<password>@<cluster-url>?writeConcern=majority";
 
 const client = new MongoClient(uri);
 
-import { MongoClient } from "mongodb";
+// Access a collection from a database
 const database = client.db("<databaseName>");
 const collection = database.collection("<collectionName>");
 
 async function run() {
   try {
     // start listIndexes example
+    // List the indexes on the collection and output them as an array
     const result = await collection.listIndexes().toArray();
+    
+    // Print the list of indexes
     console.log("Existing indexes:\n");
     for(const doc in result){
         console.log(doc);
     }
     // end listIndexes example
   } finally {
+    // Close the connection after the operation completes
     await client.close();
   }
 }
+// Run the program and print any errors
 run().catch(console.dir);