feat(useWindowScroll): add useWindowScroll

.prettierrc

@@ -1,7 +1,7 @@
 {
-    "trailingComma": "es5",
     "singleQuote": true,
     "printWidth": 120,
     "tabWidth": 2,
-    "semi": false
+    "semi": false,
+    "trailingComma": "none"
 }

src/index.ts

@@ -1,2 +1,3 @@
 export * from './useTitle'
 export * from './useEvent'
+export * from './useWindowScroll'

src/useWindowScroll.ts

@@ -0,0 +1,15 @@
+import { reactive, toRefs } from 'vue'
+import { useEvent } from './useEvent'
+import { ScrollState } from './useScroll'
+
+export function useWindowScroll(): ScrollState {
+  const state = reactive({
+    x: 0,
+    y: 0
+  })
+  useEvent('scroll', () => {
+    state.x = window.scrollX
+    state.y = window.scrollY
+  })
+  return toRefs(state)
+}