docs: add missing errorBtnText slot option in API page

Author: PeachScript

docs/api/README.md

@@ -27,6 +27,8 @@ The `infinite` event will be fired if the scroll distance is less than this valu
 
 This property is used to set the loading animation, you can choose one from the internal spinners that you like, you can also customize it with a [named slot](#spinner-2) that called `spinner`.
 
+- See also: [Configure Load Messages](../guide/configure-load-msg.md)
+
 ### direction
 
 - Type: `String`
@@ -179,6 +181,18 @@ Configure the default content for `error` slot.
 
 - See also: [Slots - error](#error)
 
+### slots.errorBtnText
+
+- Type: `String`
+- Default: `Retry`
+- Details:
+
+Configure the default text for retry button in the default `error` slot. Please note, it won't work if you customize the `error` slot, you need to configure retry button yourself.
+
+- See also:
+  - [Slots - error](#error)
+  - [Configure Load Messages](../guide/configure-load-msg.md)
+
 ### slots.spinner
 
 - Type: `String` | `Vue Component`

docs/zh/api/README.md

@@ -27,6 +27,8 @@ sidebar: auto
 
 此选项用于设置加载动画，你可以从内置选项中选择一个你喜欢的，你也可以通过名为 `spinner` 的[具名插槽](#spinner-2)来进行自定义。
 
+- 参考：[配置加载提示](../guide/configure-load-msg.md)
+
 ### direction
 
 - 类型：`String`
@@ -179,6 +181,18 @@ sidebar: auto
 
 - 参考：[插槽 - error](#error)
 
+### slots.errorBtnText
+
+- 类型：`String`
+- 默认值：`Retry`
+- 详细：
+
+配置默认 `error` 插槽中重试按钮的显示文案。请注意，如果你自定义了 `error` 插槽的内容，此配置将没有任何作用，你需要自行创建重试按钮。
+
+- 参考：
+  - [插槽 - error](#error)
+  - [配置加载提示](../guide/configure-load-msg.md)
+
 ### slots.spinner
 
 - 类型：`String` | `Vue Component`