docs(@ngtools/webpack): add Ivy linker setup documentation to readme

When not using the Angular CLI, the Babel-based Ivy linker is also required to successfully build an application. A section describing the setup of the linker in addition to the Angular compiler plugin has now been included with links to the AIO documentation and the babel-loader for additional information.

(cherry picked from commit f595936)

Author: clydin

packages/ngtools/webpack/README.md

@@ -1,6 +1,9 @@
 # Angular Compiler Webpack Plugin
 
 Webpack 5.x plugin for the Angular Ahead-of-Time compiler. The plugin also supports Angular JIT mode.
+When this plugin is used outside of the Angular CLI, the Ivy linker will also be needed to support
+the usage of Angular libraries. An example configuration of the Babel-based Ivy linker is provided
+in the linker section. For additional information regarding the linker, please see: https://v13.angular.io/guide/creating-libraries#consuming-partial-ivy-code-outside-the-angular-cli
 
 ## Usage
 
@@ -13,6 +16,7 @@ exports = {
   /* ... */
   module: {
     rules: [
+      /* ... */
       {
         test: /\.[jt]sx?$/,
         loader: '@ngtools/webpack',
@@ -23,6 +27,7 @@ exports = {
   plugins: [
     new AngularWebpackPlugin({
       tsconfig: 'path/to/tsconfig.json',
+      // ... other options as needed
     }),
   ],
 };
@@ -38,3 +43,38 @@ The loader works with webpack plugin to compile the application's TypeScript. It
 - `directTemplateLoading` [default: `true`] - Causes the plugin to load component templates (HTML) directly from the filesystem. This is more efficient if only using the `raw-loader` to load component templates. Do not enable this option if additional loaders are configured for component templates.
 - `fileReplacements` [default: none] - Allows replacing TypeScript files with other TypeScript files in the build. This option acts on fully resolved file paths.
 - `inlineStyleFileExtension` [default: none] - When set inline component styles will be processed by Webpack as files with the provided extension.
+
+## Ivy Linker
+
+The Ivy linker can be setup by using the Webpack `babel-loader` package.
+If not already installed, add the `babel-loader` package using your project's package manager.
+Then in your webpack config, add the `babel-loader` with the following configuration.
+If the `babel-loader` is already present in your configuration, the linker plugin can be added to
+the existing loader configuration as well.
+Enabling caching for the `babel-loader` is recommended to avoid reprocessing libraries on
+every build.
+For additional information regarding the `babel-loader` package, please see: https://github.com/babel/babel-loader/tree/main#readme
+
+```typescript
+import linkerPlugin from '@angular/compiler-cli/linker/babel';
+
+exports = {
+  /* ... */
+  module: {
+    rules: [
+      /* ... */
+      {
+        test: /\.[cm]?js$/,
+        use: {
+          loader: 'babel-loader',
+          options: {
+            cacheDirectory: true,
+            compact: false,
+            plugins: [linkerPlugin],
+          },
+        },
+      },
+    ],
+  },
+};
+```