Alter: title is not a required prop (#13360)

* Alter: title is not a required prop

* update docs

examples/docs/en-US/alert.md

@@ -208,7 +208,7 @@ Description includes a message with more detailed information.
 ### Attributes
 | Attribute      | Description          | Type      | Accepted Values       | Default  |
 |---------- |-------------- |---------- |--------------------------------  |-------- |
-| **title** | title **REQUIRED** | string | — | — |
+| title     | title         | string | — | — |
 | type | component type | string | success/warning/info/error | info |
 | description | descriptive text. Can also be passed with the default slot | string | — | — |
 | closable | if closable or not | boolean | — | true |

examples/docs/es/alert.md

@@ -210,7 +210,7 @@ Descripción incluye un mensaje con información más detallada.
 ### Atributos
 | Atributo    | Descripción                              | Tipo    | Valores aceptados          | Por defecto |
 | ----------- | ---------------------------------------- | ------- | -------------------------- | ----------- |
-| title       | título. Requerido                        | string  | —                          | —           |
+| title       | título                                   | string  | —                          | —           |
 | type        | tipo de componente                       | string  | success/warning/info/error | info        |
 | description | texto descriptivo. También puede ser pasado con el slot por defecto | string  | —                          | —           |
 | closable    | si se puede cerrar o no                  | boolean | —                          | true        |

examples/docs/zh-CN/alert.md

@@ -202,7 +202,7 @@
 ### Attributes
 | 参数      | 说明          | 类型      | 可选值                           | 默认值  |
 |---------- |-------------- |---------- |--------------------------------  |-------- |
-| **title** | 标题，**必选参数** | string | — | — |
+| title     | 标题           | string | — | — |
 | type | 主题 | string | success/warning/info/error | info |
 | description | 辅助性文字。也可通过默认 slot 传入 | string | — | — |
 | closable | 是否可关闭 | boolean | — | true |

packages/alert/src/main.vue

@@ -32,8 +32,7 @@
     props: {
       title: {
         type: String,
-        default: '',
-        required: true
+        default: ''
       },
       description: {
         type: String,