Add Proxmox VE Helper-Script (#473)

docs/contributing/community.md

@@ -4,3 +4,4 @@ The following is a list of resources made by happy users of Opengist. Feel free
 
 - [Aetherinox/opengist-debian](https://github.com/Aetherinox/opengist-debian) - A Debian package for Opengist
 - [How to Install Opengist on Your Synology NAS](https://mariushosting.com/how-to-install-opengist-on-your-synology-nas/) - A guide to install Opengist on a Synology NAS
+- [Proxmox VE Helper-Script](https://community-scripts.github.io/ProxmoxVE/scripts?id=opengist) - A script to install Opengist on Proxmox VE