docs: update

docs/getting-started.en-US.md

@@ -39,6 +39,18 @@ yarn start
 # Or use HMR mode by: yarn run hmr
 ```
 
+**Multiple projects**
+
+```bash
+yarn global add @angular/cli
+ng new my-workspace --no-create-application --package-manager yarn
+cd my-workspace
+ng g application mgr --style less --routing
+ng add ng-alain
+yarn mgr:start
+# Or use HMR mode by: yarn run mgr:hmr
+```
+
 > Please refer to [Schematics](/cli) for more details.
 
 ### Clone the Git Repository

docs/getting-started.zh-CN.md

@@ -46,17 +46,23 @@ NG-ALAIN 必须先创建一个全新的 Angular 项目，可以通过终端窗
 
 ```bash
 ng new my-project --style less --routing --package-manager yarn
+cd my-project
+# 或多重项目
+ng new my-workspace --no-create-application --package-manager yarn
+cd my-workspace
+ng g application mgr --style less --routing
 ```
 
 > 如果你想了解 `--style`、`--routing` 参数，请参考 [ng new](https://angular.io/cli/new#options) 文档。
 
 接下来只需要将 NG-ALAIN 添加到 `my-project` 项目中即可，在 `my-project` 目录下通过终端窗口中运行：
 
 ```bash
-cd my-project
 ng add ng-alain
 ```
 
+> 若多重项目时，需要提供具体的项目名称。
+
 NG-ALAIN 会询问是否需要一些额外的插件，一开始完全可以一路回车，这些插件都是可插拔，后期可以自行添加与移除。
 
 > 以上只会生成干净的项目，可以直接用于生产环境中。你可能在[预览](https://ng-alain.gitee.io/)上看到许多示例页，它们全都可以在 [Github](https://github.com/ng-alain/ng-alain) 查看到源代码，当然也可以通过 Git 克隆代码的形式获得：

schematics/ng-add/index.ts

@@ -103,11 +103,6 @@ export default function (options: NgAddOptions): Rule {
       if (pkg.devDependencies['ng-alain']) {
         throw new SchematicsException(`Already an NG-ALAIN project and can't be executed again: ng add ng-alain`);
       }
-      if (!tree.exists('src/index.html')) {
-        throw new SchematicsException(
-          `NG-ALAIN must be attached to a new Angular project, so you need to use 'ng new projectName' to build a new Angular project, or specify the project name to be attached`
-        );
-      }
     }
 
     let ngCoreVersion = pkg.dependencies['@angular/core'] as string;