fix(docs): improve a11y of footer with role="list"

QList used to have role="list" by default, added with #14609. 
But, it was later removed with #14784 since it's also used with the menu role commonly.
So, now QItems have role="listitem" but their parent(QList) doesn't have the list role, which is invalid.

docs/src/layouts/doc-layout/DocPageFooter.vue

@@ -2,7 +2,7 @@
   <div class="doc-page-footer doc-brand">
     <template v-if="fullscreen">
       <nav class="doc-page-footer__nav" v-once>
-        <q-list v-for="entry in links" :key="entry.name">
+        <q-list v-for="entry in links" :key="entry.name" role="list">
           <q-item-label
             class="doc-page-footer__title doc-page-footer__margin row items-end text-weight-bold letter-spacing-225 q-mb-md"
           >{{ entry.name }}</q-item-label>