[Docs]Fix the error in the documentation (#3057)

packages/progress/en-US.md

@@ -53,7 +53,7 @@ Use `pivot-text` to custom text，use `color` to custom bar color
 | Attribute | Description | Type | Default |
 |------|------|------|------|
 | inactive | Whether to be gray | `Boolean` | `false` |
-| percentage | Percentage | `Number` | `false` |
+| percentage | Percentage | `Number` | `0` |
 | show-pivot | Whether to show text | `Boolean` | `true` |
 | color | Color | `String` | `#1989fa` |
 | pivot-text | Text | `String` | percentage |

packages/progress/zh-CN.md

@@ -55,7 +55,7 @@ Vue.use(Progress);
 | 参数 | 说明 | 类型 | 默认值 | 版本 |
 |------|------|------|------|------|
 | inactive | 是否置灰 | `Boolean` | `false` | - |
-| percentage | 进度百分比 | `Number` | `false` | - |
+| percentage | 进度百分比 | `Number` | `0` | - |
 | show-pivot | 是否显示进度文字 | `Boolean` | `true` | - |
 | color | 进度条颜色 | `String` | `#1989fa` | - |
 | text-color | 进度条文字颜色 | `String` | `#fff` | - |