docs: describe how to configure CommonJS modules (angular#37331)

In version 10, we have a new option for the `angular.json` file,
`allowedCommonJsDependencies`, so users can opt in to support
CommonJS modules.

PR Close angular#37331

aio/content/guide/build.md

@@ -262,6 +262,33 @@ Each budget entry is a JSON object with the following properties:
 
  </table>
 
+{@a commonjs }
+## Configuring CommonJS dependencies
+
+<div class="alert is-important">
+
+It is recommended that you avoid depending on CommonJS modules in your Angular applications.
+Depending on CommonJS modules can prevent bundlers and minifiers from optimizing your application, which results in larger bundle sizes.
+Instead, it is recommended that you use [ECMAScript modules](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import) in your entire application.
+For more information, see [How CommonJS is making your bundles larger](https://web.dev/commonjs-larger-bundles/).
+
+</div>
+
+The Angular CLI outputs warnings if it detects that your browser application depends on CommonJS modules.
+To disable these warnings, you can add the CommonJS module name to `allowedCommonJsDependencies` option in the `build` options located in `angular.json` file.
+
+<code-example lang="json">
+"build": {
+  "builder": "@angular-devkit/build-angular:browser",
+  "options": {
+     "allowedCommonJsDependencies": [
+        "lodash"
+     ]
+     ...
+   }
+   ...
+},
+</code-example>
 
 {@a browser-compat}