docs: update Input docs for default size in Form (#34537)

components/input/index.en-US.md

@@ -29,7 +29,7 @@ A basic widget for getting the user input is a text field. Keyboard and mouse ca
 | showCount | Whether show text count | boolean \| { formatter: ({ count: number, maxLength?: number }) => ReactNode } | false | 4.18.0 |
 | status | Set validation status | 'error' \| 'warning' | - | 4.19.0 |
 | prefix | The prefix icon for the Input | ReactNode | - |  |
-| size | The size of the input box. Note: in the context of a form, the `large` size is used | `large` \| `middle` \| `small` | - |  |
+| size | The size of the input box. Note: in the context of a form, the `middle` size is used | `large` \| `middle` \| `small` | - |  |
 | suffix | The suffix icon for the Input | ReactNode | - |  |
 | type | The type of input, see: [MDN](https://developer.mozilla.org/docs/Web/HTML/Element/input#Form_%3Cinput%3E_types)( use `Input.TextArea` instead of `type="textarea"`) | string | `text` |  |
 | value | The input content value | string | - |  |

components/input/index.zh-CN.md

@@ -30,7 +30,7 @@ cover: https://gw.alipayobjects.com/zos/alicdn/xS9YEJhfe/Input.svg
 | showCount | 是否展示字数 | boolean \| { formatter: ({ count: number, maxLength?: number }) => ReactNode } | false | 4.18.0 |
 | status | 设置校验状态 | 'error' \| 'warning' | - | 4.19.0 |
 | prefix | 带有前缀图标的 input | ReactNode | - |  |
-| size | 控件大小。注：标准表单内的输入框大小限制为 `large` | `large` \| `middle` \| `small` | - |  |
+| size | 控件大小。注：标准表单内的输入框大小限制为 `middle` | `large` \| `middle` \| `small` | - |  |
 | suffix | 带有后缀图标的 input | ReactNode | - |  |
 | type | 声明 input 类型，同原生 input 标签的 type 属性，见：[MDN](https://developer.mozilla.org/zh-CN/docs/Web/HTML/Element/input#属性)(请直接使用 `Input.TextArea` 代替 `type="textarea"`) | string | `text` |  |
 | value | 输入框内容 | string | - |  |