enhance configuration page

Author: commit111

docs/concepts/configuration.md

@@ -6,13 +6,9 @@ sidebar_position: 225
 
 # Configuration
 
-Defang allows you to configure your application using environment variables. You can set environment variables in your [`compose.yaml` file](./compose.md), or in your [Pulumi program](./pulumi.md). Using Pulumi gives you the advantage of being able to manage your environment variables across different environments using Pulumi stacks.
+Defang allows you to configure your application using environment variables. You can set environment variables in your [`compose.yaml` file](./compose.md), or in your [Pulumi program](#using-config-with-pulumi).
 
-:::tip Sample
-You can find a sample of how to set environment variables with Pulumi [here](https://github.com/DefangLabs/defang/tree/main/samples/nodejs/remix-aiven-postgres).
-:::
-
-# Sensitive Config aka Secrets
+# Sensitive Config (aka Secrets)
 
 The Defang CLI allows you to securely store sensitive information such as API keys, passwords, and other credentials. To do so, run:
 
@@ -44,6 +40,10 @@ services:
 
 Use the `defang config` command of the Defang CLI to manage the values.
 
+:::tip
+You can find a sample of how to set sensitive config values [here](https://github.com/DefangLabs/samples/tree/main/samples/nodejs-openai).
+:::
+
 ## Interpolation
 
 Environment variables are set within the *environment* section of a service in a `compose.yaml` file. Any variables declared here will become available within the service container.
@@ -62,18 +62,24 @@ In the example above, if we assume the value of the configuration variable ***US
 
 During `defang compose up` all variable references will be replaced with the actual value and made available in the container. If any referenced variable is not found the `defang compose up` command will be canceled.
 
+## Using Config with Pulumi 
+In Defang, using config with [Pulumi](./pulumi.md) gives you the advantage of being able to manage your environment variables across different environments using Pulumi stacks.
+
+:::tip
+You can find a sample of how to set environment variables with Pulumi [here](https://github.com/DefangLabs/samples/tree/main/samples/pulumi-remix-postgres).
+:::
+
 ## Connecting Services
 
 If you have created a service before a secret you can connect it by running the `defang compose start` command if using the [`defang compose` workflow](./compose.md). If you are using the [Pulumi-based workflow](./pulumi.md) you will need to redeploy using Pulumi.
 
-:::tip Sample
-You can find a sample of how to set sensitive config values [here](https://github.com/DefangLabs/defang/tree/main/samples/nodejs/ChatGPT%20API).
-:::
-
 ## Providers
 
 Here are the different ways sensitive config values are stored depending on the provider you are using:
 
     * [AWS](../providers/aws/aws.md#secrets)
+    * [DigitalOcean](../providers/digitalocean#secrets)
+    * [GCP](../providers/gcp#secrets)
+