docs(configuration): update devServer.headers (#5598)

* docs(configuration): update `devServer.headers`

* docs(configuration): update `devServer.headers`

Author: snitin315

src/content/configuration/dev-server.mdx

@@ -635,7 +635,7 @@ W> Don't specify `https.ca` and `https.cacert` options together, if specified `h
 
 ## devServer.headers
 
-`function` `object`
+`array` `function` `object`
 
 Adds headers to all responses:
 
@@ -652,6 +652,28 @@ module.exports = {
 };
 ```
 
+You can also pass an array:
+
+**webpack.config.js**
+
+```javascript
+module.exports = {
+  //...
+  devServer: {
+    headers: [
+      {
+        key: 'X-Custom',
+        value: 'foo',
+      },
+      {
+        key: 'Y-Custom',
+        value: 'bar',
+      },
+    ],
+  },
+};
+```
+
 You can also pass a function:
 
 ```javascript