feat(steps): 增加types

@types/index.d.ts

@@ -35,6 +35,7 @@ export { default as AtToast } from './toast'
 export { default as AtTabsPane } from './tabs-pane'
 export { default as AtSwipeAction } from './swipe-action'
 export { default as AtAccordion } from './accordion'
+export { default as AtSteps } from './steps'
 
 export declare const AtModalHeader: ComponentClass
 export declare const AtModalAction: ComponentClass

@types/steps.d.ts

@@ -0,0 +1,38 @@
+import { MouseEvent, ComponentClass } from 'react'
+import { BaseEventFunction } from '@tarojs/components/types/common'
+
+import AtComponent from './base'
+
+export interface Icon {
+  value?: string
+
+  activeColor?: string
+
+  inactiveColor?: string
+
+  size?: string|number
+}
+
+export interface Item {
+  title?: string
+
+  desc?: string
+
+  icon?: Icon
+
+  success?: boolean
+
+  error?: boolean
+}
+
+export interface AtStepsProps extends AtComponent {
+  current?: number
+
+  items?: Array<Item>
+
+  onChange: (current: number, event: BaseEventFunction) => void
+}
+
+declare const AtSteps: ComponentClass<AtStepsProps>
+
+export default AtSteps