init (beta) does not work

**Description:**
trying to use the new `ionic init `command does not work as expected.

After creating a simple ng app with `ng new` we try to add with ionic init the ionic project.

This is the output we have:
```
ionic init
? Project name: web-client-ionic
[WARN] Could not determine project type.

Please choose a project type from the list.

? Project type: @ionic/angular (angular)
[OK] Your Ionic project has been initialized!
```
This is only creating the `ionic.config.json` file, but it does not install any dependencies.

On running now `ionic serve` we get this
```
ionic serve
> ng run app:serve --host=localhost --port=8100
[ng] An unhandled exception occurred: Project does not exist.
[ng] See "/private/var/folders/t0/25v77r0n1h52ln6mmjvnllzm0000gn/T/ng-1qK8zi/angular-errors.log" for further details.

[ERROR] ng has unexpectedly closed (exit code 127).

The Ionic CLI will exit. Please check any output above for error details.
```
Also after installaing @ionic/angular and @ionic/angular-toolkit we run into the same error

I know the function is in beta, but perhaps this is not an expecting error from your side

thx

使用 `ng new` 重現回報的流程，接著執行 `ionic init` 和 `ionic serve`，以命令輸出作為起點。追蹤 `init` 和 `serve` 的進入點，以判斷為什麼初始化的 Angular 專案無法被辨識；完成標準是產生的專案可以執行 `ionic serve`，且不會出現「Project does not exist」錯誤。

由索引模型根據 Issue 內容生成。