Add docs for API setup Vercel Connection

docs/integrations/app-connections/vercel.mdx

@@ -32,23 +32,62 @@ Infisical supports connecting to Vercel using an API Token to securely sync your
         You should now see your newly created token in the list of API tokens on the Vercel dashboard.
         ![Vercel Connection Created](/images/app-connections/vercel/vercel-token-created.png)
     </Step>
-    <Step title="Navigate to App Connections">
+    <Step title="Setup Vercel Connection in Infisical">
+        <Tabs>
+            <Tab title="Infisical UI">
+                1. Navigate to App Connections
                     In your Infisical dashboard, go to **Organization Settings** and select the **App Connections** tab.
                     ![App Connections Tab](/images/app-connections/general/add-connection.png)
-    </Step>
+                2. Add Connection
-    <Step title="Add Connection">
                     Click the **+ Add Connection** button and select the **Vercel Connection** option from the available integrations.
                     ![Select Vercel Connection](/images/app-connections/vercel/vercel-app-connection-option.png)
-    </Step>
+                3. Fill the Vercel Connection Modal
-    <Step title="Fill the Vercel Connection Modal">
                     Complete the Vercel Connection form by entering:
                     - A descriptive name for the connection
                     - The API Token you generated in steps 3-4
                     - An optional description for future reference
                     ![Vercel Connection Modal](/images/app-connections/vercel/vercel-app-connection-modal.png)
-    </Step>
+                4. Connection Created
-    <Step title="Connection Created">
                     After clicking Create, your **Vercel Connection** is established and ready to use with your Infisical projects.
                     ![Vercel Connection Created](/images/app-connections/vercel/vercel-app-connection-created.png)
+            </Tab>
+            <Tab title="API">
+                To create a Vercel Connection, make an API request to the [Create Vercel
+                Connection](/api-reference/endpoints/app-connections/vercel/create) API endpoint.
+
+                ### Sample request
+
+                ```bash Request
+                curl    --request POST \
+                        --url https://app.infisical.com/api/v1/app-connections/vercel \
+                        --header 'Content-Type: application/json' \
+                        --data '{
+                            "name": "my-vercel-connection",
+                            "method": "api-token",
+                            "credentials": {
+                                "apiToken": "...",
+                            }
+                        }'
+                ```
+
+                ### Sample response
+
+                ```bash Response
+                {
+                    "appConnection": {
+                        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
+                        "name": "my-vercel-connection",
+                        "version": 123,
+                        "orgId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
+                        "createdAt": "2025-04-01T05:31:56Z",
+                        "updatedAt": "2025-04-01T05:31:56Z",
+                        "app": "vercel",
+                        "method": "api-token",
+                        "credentials": {}
+                    }
+                }
+                ```
+            </Tab>
+        </Tabs>
     </Step>
 </Steps>