docs: Add YugabyteDB smart driver features to Sequelize documentation

- Added note about smart driver features in Step 2
- New section: Using YugabyteDB Smart Driver features
  - Load balancing configuration and modes
  - Topology awareness for multi-region deployments
  - Connection string examples with smart driver parameters
  - Environment variables reference table
- Examples showing how to enable load balancing with process.env
- Documentation for all PGLOADBALANCE modes
- Examples for topology-aware routing
- Complete environment variables reference

This update helps developers leverage YugabyteDB's smart driver capabilities
for better performance, high availability, and geo-distributed applications.

Author: krishna-yb

docs/content/stable/develop/drivers-orms/nodejs/sequelize.md

@@ -88,6 +88,16 @@ The following code creates an Employees model to store and retrieve employee inf
 - The actual table is created by calling the `Employee.sync()` API in the `createTableAndInsert()` function. This also inserts the data for three employees into the table using the `Employee.create()` API.
 - Finally, you can retrieve the information of all employees using `Employee.findAll()`.
 
+{{< note title="YugabyteDB Smart Driver Features" >}}
+The `sequelize-yugabytedb` package uses the YugabyteDB smart driver (`@yugabytedb/pg`) which provides advanced features like:
+
+- **Load Balancing**: Automatically distribute queries across cluster nodes
+- **Topology Awareness**: Route queries based on node location and availability
+- **Connection Management**: Automatic failover and node discovery
+
+These features are configured via environment variables or connection parameters. See the examples below for configuration options.
+{{< /note >}}
+
 Add the code in the `example.js` file.
 
 ```js
@@ -189,6 +199,100 @@ Employees Details:
 ]
 ```
 
+## Using YugabyteDB Smart Driver features
+
+The `sequelize-yugabytedb` package includes the YugabyteDB smart driver which provides cluster-aware connection management. You can enable these features using environment variables or configuration parameters.
+
+### Load balancing
+
+Configure load balancing to distribute queries across all nodes in your YugabyteDB cluster:
+
+```js
+const { Sequelize, DataTypes } = require('sequelize-yugabytedb')
+
+// Set load balancing before creating connection
+process.env.PGLOADBALANCE = 'any';  // Options: any, prefer-primary, prefer-rr, only-primary, only-rr
+process.env.PGYBSERVERSREFRESHINTERVAL = '5';  // Refresh cluster topology every 5 seconds
+
+const sequelize = new Sequelize('yugabyte', 'yugabyte', 'yugabyte', {
+   host: 'localhost',
+   port: '5433',
+   dialect: 'postgres'
+})
+```
+
+**Load balance modes:**
+
+- `any`: Distribute queries across all nodes (recommended for best performance)
+- `prefer-primary`: Prefer primary nodes, fall back to read replicas
+- `prefer-rr`: Prefer read replicas, fall back to primary nodes  
+- `only-primary`: Use only primary nodes
+- `only-rr`: Use only read replica nodes
+
+### Topology awareness
+
+For multi-region deployments, use topology awareness to route queries to nodes in specific regions or zones:
+
+```js
+// Route queries to nodes in specific cloud region/zone
+process.env.PGTOPOLOGYKEYS = 'aws.us-east-2.us-east-2a';
+process.env.PGFALLBACKTOTOPOLOGYKEYSONLY = 'false';  // Allow fallback to other zones
+
+const sequelize = new Sequelize('yugabyte', 'yugabyte', 'yugabyte', {
+   host: 'localhost',
+   port: '5433',
+   dialect: 'postgres'
+})
+```
+
+### Connection string with smart driver parameters
+
+Alternatively, you can specify load balancing parameters directly in the connection string:
+
+```js
+const connectionString = 
+  'postgres://yugabyte:yugabyte@localhost:5433/yugabyte' +
+  '?loadBalance=any' +
+  '&topologyKeys=aws.us-east-2.us-east-2a' +
+  '&ybServersRefreshInterval=5' +
+  '&failedHostReconnectDelaySecs=5';
+
+const sequelize = new Sequelize(connectionString, {
+   dialect: 'postgres',
+   pool: {
+      max: 10,
+      min: 2,
+      idle: 10000,
+      acquire: 30000
+   }
+});
+```
+
+### Environment variables
+
+The YugabyteDB smart driver recognizes these PostgreSQL-compatible environment variables:
+
+| Variable | Description | Default |
+| :--- | :--- | :--- |
+| `PGHOST` | Database host | `localhost` |
+| `PGPORT` | Database port | `5433` |
+| `PGUSER` | Database user | `yugabyte` |
+| `PGPASSWORD` | Database password | `yugabyte` |
+| `PGDATABASE` | Database name | `yugabyte` |
+| `PGLOADBALANCE` | Load balancing mode | `false` |
+| `PGTOPOLOGYKEYS` | Topology-aware routing keys | - |
+| `PGYBSERVERSREFRESHINTERVAL` | Cluster topology refresh interval (seconds) | `5` |
+| `PGFAILEDHOSTRECONNECTDELAYSECS` | Failed host reconnect delay (seconds) | `5` |
+
+You can set these in your shell or in a `.env` file:
+
+```sh
+export PGHOST=localhost
+export PGPORT=5433
+export PGLOADBALANCE=any
+export PGYBSERVERSREFRESHINTERVAL=5
+```
+
 ## Specifying SSL configuration
 
 This configuration can be used while connecting to a YugabyteDB Aeon cluster or a local YB cluster with SSL enabled.