doc: update menu

Author: tangjinzhou

components/menu/index.en-US.md

@@ -43,7 +43,7 @@ More layouts with navigation: [Layout](/components/layout).
 | mode | type of the menu; `vertical`, `horizontal`, and `inline` modes are supported | `vertical` \| `horizontal` \| `inline` | `vertical` |
 | multiple | Allow selection of multiple items | boolean | false |
 | openKeys(v-model) | array with the keys of currently opened sub menus | string\[] |  |
-| overflowedIndicator | Customized icon when menu is collapsed | DOM | `<span>···</span>` |
+| overflowedIndicator | Customized the ellipsis icon when menu is collapsed horizontally | slot | `<EllipsisOutlined />` |
 | selectable | allow selecting menu items | boolean | true |
 | selectedKeys(v-model) | array with the keys of currently selected menu items | string\[] |  |
 | style | style of the root node | object |  |

components/menu/index.zh-CN.md

@@ -44,7 +44,7 @@ cover: https://gw.alipayobjects.com/zos/alicdn/3XZcjGpvK/Menu.svg
 | mode | 菜单类型，现在支持垂直、水平、和内嵌模式三种 | `vertical` \| `horizontal` \| `inline` | `vertical` |
 | multiple | 是否允许多选 | boolean | false |
 | openKeys(v-model) | 当前展开的 SubMenu 菜单项 key 数组 | string\[] |  |
-| overflowedIndicator | 自定义 Menu 折叠时的图标 | DOM | `<span>···</span>` |
+| overflowedIndicator | 用于自定义 Menu 水平空间不足时的省略收缩的图标 | slot | `<EllipsisOutlined />` |
 | selectable | 是否允许选中 | boolean | true |
 | selectedKeys(v-model) | 当前选中的菜单项 key 数组 | string\[] |  |
 | subMenuCloseDelay | 用户鼠标离开子菜单后关闭延时，单位：秒 | number | 0.1 |

components/menu/style/dark.less

@@ -1,4 +1,19 @@
+.accessibility-focus-dark() {
+  box-shadow: 0 0 0 2px @primary-7;
+}
+
 .@{menu-prefix-cls} {
+  &&-root:focus-visible {
+    .accessibility-focus-dark();
+  }
+
+  &-dark &-item,
+  &-dark &-submenu-title {
+    &:focus-visible {
+      .accessibility-focus-dark();
+    }
+  }
+
   // dark theme
   &&-dark,
   &-dark &-sub,

components/menu/style/index.less

@@ -6,7 +6,7 @@
 @menu-animation-duration-normal: 0.15s;
 
 .accessibility-focus() {
-  box-shadow: 0 0 0 2px @primary-1;
+  box-shadow: 0 0 0 2px @primary-2;
 }
 
 // TODO: Should remove icon style compatible in v5
@@ -315,7 +315,7 @@
         position: absolute;
         width: 6px;
         height: 1.5px;
-        background-color: currentColor;
+        background-color: currentcolor;
         border-radius: 2px;
         transition: background @animation-duration-slow @ease-in-out,
           transform @animation-duration-slow @ease-in-out, top @animation-duration-slow @ease-in-out,