docs: update Form documentation (#22427)

* Update index.en-US.md

* Update index.zh-CN.md

* Update index.en-US.md

components/form/index.en-US.md

@@ -50,7 +50,7 @@ const validateMessages = {
 <Form validateMessages={validateMessages} />;
 ```
 
-Besides,[ConfigProvider](/components/config-provider/) also provides a global configuration scheme that allows for uniform configuration error notification templates:
+Besides, [ConfigProvider](/components/config-provider/) also provides a global configuration scheme that allows for uniform configuration error notification templates:
 
 ```jsx
 const validateMessages = {
@@ -92,6 +92,12 @@ Form field component for data bidirectional binding, validation, layout, and so
 | valuePropName | Props of children node, for example, the prop of Switch is 'checked' | string | 'value' |
 | wrapperCol | The layout for input controls, same as `labelCol`. You can set `wrapperCol` on Form. If both exists, use Item first | [object](/components/grid/#Col) | - |
 
+After wrapped by `Form.Item` with `name` property, `value`(or other property defined by `valuePropName`) `onChange`(or other property defined by `trigger`) props will be added to form controls, the flow of form data will be handled by Form which will cause:
+
+1. You shouldn't use `onChange` on each form control to **collect data**(use `onValuesChange` of Form), but you can still listen to `onChange`.
+2. You cannot set value for each form control via `value` or `defaultValue` prop, you should set default value with `initialValues` of Form. Note that `initialValues` cannot be updated by `setState` dynamiclly, you should use `setFieldsValue` in that situation.
+3. You shouldn't call `setState` manually, please use `form.setFieldsValue` to change value programmatically.
+
 ### dependencies
 
 Used when there are dependencies between fields. If a field has the `dependencies` prop, this field will automatically trigger updates and validations when upstream is updated. A common scenario is a user registration form with "password" and "confirm password" fields. The "Confirm Password" validation depends on the "Password" field. After setting `dependencies`, the "Password" field update will re-trigger the validation of "Check Password". You can refer [examples](#components-form-demo-register).

components/form/index.zh-CN.md

@@ -93,6 +93,12 @@ const validateMessages = {
 | valuePropName | 子节点的值的属性，如 Switch 的是 'checked' | string | 'value' |
 | wrapperCol | 需要为输入控件设置布局样式时，使用该属性，用法同 `labelCol`。你可以通过 Form 的 `wrapperCol` 进行统一设置。当和 Form 同时设置时，以 Item 为准。 | [object](/components/grid/#Col) | - |
 
+被设置了 `name` 属性的 `Form.Item` 包装的控件，表单控件会自动添加 `value`（或 `valuePropName` 指定的其他属性） `onChange`（或 `trigger` 指定的其他属性），数据同步将被 Form 接管，这会导致以下结果：
+
+1. 你**不再需要也不应该**用 `onChange` 来做数据收集同步（你可以使用 Form 的 `onValuesChange`），但还是可以继续监听 `onChange` 事件。
+2. 你不能用控件的 `value` 或 `defaultValue` 等属性来设置表单域的值，默认值可以用 Form 里的 `initialValues` 来设置。注意 `initialValues` 不能被 `setState` 动态更新，你需要用 `setFieldsValue` 来更新。
+3. 你不应该用 `setState`，可以使用 `form.setFieldsValue` 来动态改变表单值。
+
 ### dependencies
 
 当字段间存在依赖关系时使用。如果一个字段设置了 `dependencies` 属性。那么它所依赖的字段更新时，该字段将自动触发更新与校验。一种常见的场景，就是注册用户表单的“密码”与“确认密码”字段。“确认密码”校验依赖于“密码”字段，设置 `dependencies` 后，“密码”字段更新会重新触发“校验密码”的校验逻辑。你可以参考[具体例子](#components-form-demo-register)。