docs(@angular/cli): add ng new long description

This appears to have been deleted by mistake when we switched to Yargs.

(cherry picked from commit 143fc68)

packages/angular/cli/src/commands/new/cli.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import { join } from 'node:path';
 import { Argv } from 'yargs';
 import {
   CommandModuleImplementation,
@@ -35,7 +36,7 @@ export class NewCommandModule
   command = 'new [name]';
   aliases = 'n';
   describe = 'Creates a new Angular workspace.';
-  longDescriptionPath?: string | undefined;
+  longDescriptionPath = join(__dirname, 'long-description.md');
 
   override async builder(argv: Argv): Promise<Argv<NewCommandArgs>> {
     const localYargs = (await super.builder(argv)).option('collection', {

packages/angular/cli/src/commands/new/long-description.md

@@ -0,0 +1,15 @@
+Creates and initializes a new Angular application that is the default project for a new workspace.
+
+Provides interactive prompts for optional configuration, such as adding routing support.
+All prompts can safely be allowed to default.
+
+- The new workspace folder is given the specified project name, and contains configuration files at the top level.
+
+- By default, the files for a new initial application (with the same name as the workspace) are placed in the `src/` subfolder.
+- The new application's configuration appears in the `projects` section of the `angular.json` workspace configuration file, under its project name.
+
+- Subsequent applications that you generate in the workspace reside in the `projects/` subfolder.
+
+If you plan to have multiple applications in the workspace, you can create an empty workspace by using the `--no-create-application` option.
+You can then use `ng generate application` to create an initial application.
+This allows a workspace name different from the initial app name, and ensures that all applications reside in the `/projects` subfolder, matching the structure of the configuration file.