How to use Angular Elements with Form Control?

### Describe the problem that you experienced

Hello,
Since I cannot find any information online about it - I resort to asking straight from the source.

How to convert Angular component that uses Control Value Accessor to Web Component and use it correctly? Is there any official way uncovered in the documentation?

Main issues I have seem to be:
a) Provider array in component with following construct
causes this NullInjectorError after conversion to Web Component and simply consuming it in index.html demo file
(we can assume here that conversion of other elements - without any items in providers array - are working correctly; this was succesful and relatively easy)

b) Actual consumption of converted element via formControl - I found conflicting information that Web Component can or absolutely cannot be used with Form Control, some info about adding ngDefaultControl directive to Web Component (to every element every time? seems weird but it does nothing for me either way OOTB).

Please, let's settle what is the proper approach here as the documentation seems lacking such information. It would be greatly appreciated by everyone who's trying to convert Angular lib to be widely used across platforms and frameworks.

Cheers!

### Enter the URL of the topic with the problem

https://angular.io/guide/elements#typings-for-custom-elements

### Describe what you were looking for in the documentation

_No response_

### Describe the actions that led you to experience the problem

_No response_

### Describe what you want to experience that would fix the problem

_No response_

### Add a screenshot if that helps illustrate the problem

_No response_

### If this problem caused an exception or error, please paste it here

_No response_

### If the problem is browser-specific, please specify the device, OS, browser, and version

_No response_

### Provide any additional information here in as much as detail as you can

_No response_

從 angular.io/guide/elements#typings-for-custom-elements 的 Angular Elements 指南開始，檢視已回報的 NullInjectorError 與 FormControl 使用問題。確定將以 ControlValueAccessor 為基礎的元件轉換成 web components 時官方支援的方法，然後更新文件以說明 provider 與表單控制項的行為。

由索引模型根據 Issue 內容生成。