feat: recover flip prop

src/popover/demos/enUS/flip.demo.md

@@ -0,0 +1,22 @@
+# Adjust the popover
+
+Use `flip` to decide whether to adjust, use `flipLevel` to decide the level of adjustment.
+
+```html
+<n-popover
+  trigger="click"
+  placement="bottom-start"
+  :flip="true"
+  :flip-level="1"
+>
+  <template #trigger>
+    <n-button> Offset </n-button>
+  </template>
+  <span
+    >The default level 1 is to adjust within the existing position. If the
+    existing position is not satisfied, then you can set the level to 2, which
+    will be offset appropriately at the same latitude. Note: if the popover is
+    large enough, any offset will be blocked!</span
+  >
+</n-popover>
+```

src/popover/demos/enUS/index.demo-entry.md

@@ -8,6 +8,7 @@ If you just want to display some basic text message, see [Tooltip](tooltip) inst
 
 ```demo
 basic
+flip
 trigger
 delay
 no-arrow

src/popover/demos/zhCN/flip.demo.md

@@ -0,0 +1,14 @@
+# 弹出信息的位置调整
+
+使用 `flip` 决定是否调整，使用`flipLevel`决定调整等级
+
+```html
+<n-popover trigger="click" placement="bottom-start" :flip-level="2">
+  <template #trigger>
+    <n-button> 我要调整 </n-button>
+  </template>
+  <span
+    >默认等级1是在已有位置内调整，如若已有位置不满足还是被遮挡了，可以设置等级为2，会在同纬度进行适当偏移的。注意：如果弹出信息足够大，怎么偏移都是会被遮挡哦！</span
+  >
+</n-popover>
+```

src/popover/demos/zhCN/index.demo-entry.md

@@ -8,6 +8,7 @@ Popover 在内容周围弹出一些隐藏的信息。Popover 里面没什么内
 
 ```demo
 basic
+flip
 trigger
 delay
 no-arrow

src/popover/src/PopoverBody.tsx

@@ -305,6 +305,7 @@ export default defineComponent({
         y: this.y,
         flip: this.flip,
         placement: this.placement,
+        flip: this.flip,
         flipLevel: this.flipLevel,
         containerClass: this.namespace,
         ref: 'followerRef',