docs: update numeric type

src/index-bar/README.md

@@ -65,7 +65,7 @@ export default {
 | Attribute | Description | Type | Default |
 |------|------|------|------|
 | index-list | Index List | *string[] \| number[]* | `A-Z` |
-| z-index | z-index | *string \| number* | `1` |
+| z-index | z-index | *number \| string* | `1` |
 | sticky | Whether to enable anchor sticky top | *boolean* | `true` |
 | sticky-offset-top `v2.0.7` | Anchor offset top when sticky | *number* | `0` |
 | highlight-color | Index character highlight color | *string* | `#07c160` | - |
@@ -74,7 +74,7 @@ export default {
 
 | Attribute | Description | Type | Default |
 |------|------|------|------|
-| index | Index | *string \| number* | - |
+| index | Index | *number \| string* | - |
 
 ### IndexBar Events
 

src/index-bar/README.zh-CN.md

@@ -69,7 +69,7 @@ export default {
 | 参数 | 说明 | 类型 | 默认值 |
 |------|------|------|------|
 | index-list | 索引字符列表 | *string[] \| number[]* | `A-Z` |
-| z-index | z-index 层级 | *string \| number* | `1` |
+| z-index | z-index 层级 | *number \| string* | `1` |
 | sticky | 是否开启锚点自动吸顶 | *boolean* | `true` |
 | sticky-offset-top `v2.0.7` | 锚点自动吸顶时与顶部的距离 | *number* | `0` |
 | highlight-color | 索引字符高亮颜色 | *string* | `#07c160` |
@@ -78,7 +78,7 @@ export default {
 
 | 参数 | 说明 | 类型 | 默认值 |
 |------|------|------|------|
-| index | 索引字符 | *string \| number* | - |
+| index | 索引字符 | *number \| string* | - |
 
 ### IndexBar Events