Start on Vue 3 changes

src/components/welcome_headers/WelcomeHeaderRoom.vue

@@ -2,7 +2,7 @@
   <div class="created-room-welcome-header">
     <div>{{ $t("room_welcome.info") }}</div>
     <div class="mt-2" v-if="roomJoinRule == 'public'">
-      <i18n path="room_welcome.join_public" tag="span">
+      <i18n-t keypath="room_welcome.join_public" tag="span">
         <template v-slot:link>
           <div style="position:relative;display:inline-block">
             <a @click.stop="copyPublicLink" :href="publicRoomLink" class="text-break">{{ publicRoomLink }}</a>
@@ -17,7 +17,7 @@
             >
           </div>
         </template>
-      </i18n>
+      </i18n-t>
     </div>
     <div class="mt-2" v-else-if="roomJoinRule == 'invite'">
       {{ $t("room_welcome.join_invite") }}