How to install Portainer on a Synology NAS using Container Manager / Docker Compose

Watch a guy with a cold clear his throat a lot while installing Portainer using just the built in Synology application Container Manager. A little help from Text Edit too. Credit to the composerize website for providing the much helpful docker-run to docker-compose translation service.
While Portainer and Container Manager are similar, there might be a few uses for Portainer. You can access what are known as "docker volumes" in Portainer without needing to SSH into your NAS. I don't believe Container Manager has that ability. You can also follow a lot of portainer tutorials out there. If you're just getting started in this container world, it might be easier to follow those than to try to figure out how a portainer tutorial could work in Container Manager.
Don't forget to type in HTTPS when trying to access portainer. And make sure to allow port 9443 in your Synology Firewall if you're using it. Not your router's firewall, just the one in Synology. It's in your Synology security settings. If you don't have it turned on then don't worry about it. Maybe worry about other things, but not port 9443.