(Tutorial) Add button for SSO that works even with Android

[M4TH1EU]

Add in General -> Branding -> Login disclaimer :

<form action="https://jellyfin.<your domain>.com/sso/OID/start/<your provider name>">
  <button class="raised block emby-button button-submit" 
          onclick="if (!localStorage.getItem('_deviceId2') && window.NativeShell?.AppHost?.deviceId) { localStorage.setItem('_deviceId2', window.NativeShell.AppHost.deviceId()); }" 
          target="_self" 
          style="display: flex; align-items: center; justify-content: center; gap: 10px; padding: 12px 20px; font-size: 16px;">
    <span class="material-icons shield" aria-hidden="true"></span>
    <span>Connect using SSO</span>
  </button>
</form>

Thanks to : #61 (comment)