How can I make an init script (or daemon?) for an arbitrary program that runs in the background?

Question

I want to use Markdoc, a system that converts markdown files into wiki pages. Markdoc comes with its own server. I created a new user for the wiki and put the wiki files into that user's home folder. My current (very inelegant) solution is to su into the markdoc user I and run this command, starting the server in the background:

markdoc serve -p 8577 2>/dev/null &

Then I exit back into my normal user. In my Nginx configuration, I have this section:

server {
    listen 80; 
    server_name myserver.com;

    location / { 
        proxy_pass http://127.0.0.1:8577;
    }   
}   

This works, but I have the sneaking suspicion that it is not the accepted best practice. However, I don't know what I am looking for. Am I supposed to wrap the Markdoc server in some kind of init script? Does that make it a daemon? Can any program be a daemon, or does it have to be specifically designed for that?

I also don't think my terminology is entirely accurate. Any input would be greatly appreciated!