fix: contentBase is deprecated in Webpack v5

Webpack v5 is not using contentBase, recommended to use static option instead. Following the documentation: https://github.com/webpack/webpack-dev-server/blob/master/migration-v4.md

Author: AlejandroArcoPu

src/content/7/es/part7d.md

@@ -515,7 +515,9 @@ const config = {
   },
   // highlight-start
   devServer: {
-    contentBase: path.resolve(__dirname, 'build'),
+    static: {
+        directory: path.resolve(__dirname, 'build'),
+    },
     compress: true,
     port: 3000,
   },