fix(admin): add toggle menu button for admin navigation (#462)

src/pages/AdminSettings.vue

@@ -29,6 +29,8 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
       />
     </NcAppNavigation>
     <NcAppContent class="cm-settings cm-settings--nav">
+      <button @click="toggleNav" class="cm-settings-nav-toggle">{{ trans('Toggle menu') }}</button>
+
       <SettingsSection :hidden="section !== 'panel'">
         <SectionTitle label="Panel" />
 
@@ -628,6 +630,10 @@ const filterConfig = (value) => {
   return result
 }
 
+const toggleNav = () => {
+  document.querySelector('.cm-settings-nav .app-navigation-toggle-wrapper > button').click()
+}
+
 onMounted(async () => {
   config.value = await configStore.getAppConfig()