Update USER_SUBMITTED_GUIDES.md

USER_SUBMITTED_GUIDES.md

@@ -13,3 +13,5 @@
 [Home Assistant: Proxmox Quick Start Guide](https://www.derekseaman.com/2023/04/installing-home-assistant-on-proxmox-quick-start-guide.html)
 
 [Home Assistant: Installing Grafana (LXC) with Let’s Encrypt SSL](https://www.derekseaman.com/2023/04/home-assistant-installing-grafana-lxc.html)
+
+[Proxmox: Plex LXC with Alder Lake Transcoding](https://www.derekseaman.com/2023/04/proxmox-plex-lxc-with-alder-lake-transcoding.html)