add "cohost-like" display mode, based off of 1df79a1f12 with a minor tweak

src/components/settings_modal/tabs/general_tab.vue

@@ -104,6 +104,15 @@
     <div class="setting-item">
       <h2>{{ $t('settings.interface') }}</h2>
       <ul class="setting-list">
+        <li>
+          <ChoiceSetting
+            id="timelineStyle"
+            path="timelineStyle"
+            :options="timelineStyleOptions"
+          >
+            {{ $t('settings.timeline_style_choice') }}
+          </ChoiceSetting>
+        </li>
         <li v-if="instanceSpecificPanelPresent">
           <BooleanSetting path="hideISP">
             {{ $t('settings.hide_isp') }}