message: fix(cli): Header.vue add key attr
diff: />
  <ul class="van-doc-header__top-nav">
  - <li v-for="item in config.links" class="van-doc-header__top-nav-item">
  + <li
  + v-for="(item, index) in config.links"
  + :key="index"
  + class="van-doc-header__top-nav-item"
  + >
  <a
  class="van-doc-header__logo-link"
  target="_blank"
  <transition name="van-doc-dropdown">
  <div v-if="showVersionPop" class="van-doc-header__version-pop">
  <div
  - v-for="item in versions"
  + v-for="(item, index) in versions"
  + :key="index"
  class="van-doc-header__version-pop-item"
  @click="onSwitchVersion(item)"
  >
  