I think this is not possible to configure just with yunohosting standard tools. My guess would be you would not need yunohost to do so. I have a blog made with a static site generator and I just push the whole output to a directory under /var/www. Plus there is an nginx running as Webserver and to redirect traffic to subdomains.
Nice! I live in Germany and your situation looks similar to mine. I started with Linux 20 years ago and bought a Synology about a year ago. I have my most essential services (backup, photos, Media server and paperless) running on that machine in my local network. I started with a small VPS and a blog after this, to see if I could handle managing a server. It went well.
We have a small cabin we share with others and I wanted to set up some basic services like a calendar. Went across a post about yunohost and gave it a try.
I think this is not possible to configure just with yunohosting standard tools. My guess would be you would not need yunohost to do so. I have a blog made with a static site generator and I just push the whole output to a directory under /var/www. Plus there is an nginx running as Webserver and to redirect traffic to subdomains.