translated new folder

web/themes/custom/materiotheme/vuejs/components/User/UserFlags.vue

@@ -20,7 +20,7 @@
       </li>
       <li v-if="collsLength<15" class="create-flag">
         <input
-          placeholder="new folder"
+          :placeholder="$t('materio.new folder')"
           v-model="new_folder_name"
           @keyup.enter.prevent.stop="onCreateFlagColl"
         />