add simple red dot for chat notifs

src/components/mobile_nav/mobile_nav.js

@@ -2,6 +2,7 @@ import SideDrawer from '../side_drawer/side_drawer.vue'
 import Notifications from '../notifications/notifications.vue'
 import { unseenNotificationsFromStore } from '../../services/notification_utils/notification_utils'
 import GestureService from '../../services/gesture_service/gesture_service'
+import { mapGetters } from 'vuex'
 
 const MobileNav = {
   components: {
@@ -33,7 +34,8 @@ const MobileNav = {
     sitename () { return this.$store.state.instance.name },
     isChat () {
       return this.$route.name === 'chat'
-    }
+    },
+    ...mapGetters(['unreadChatCount'])
   },
   methods: {
     toggleMobileSidebar () {

src/components/mobile_nav/mobile_nav.vue

@@ -16,6 +16,10 @@
             @click.stop.prevent="toggleMobileSidebar()"
           >
             <i class="button-icon icon-menu" />
+            <div
+              v-if="unreadChatCount"
+              class="alert-dot"
+            />
           </a>
           <router-link
             v-if="!hideSitename"