Further question: So, now that I have been able to identify where my header.tmpl file should be located, I am now trying to figure out how I call out my custom css files, specifically what path to put in my <link> tags, and really for any additional assets I want to have. I am pretty positive there is no info on this on the documentation ({{AppSubUrl}} doesn’t seem to work, it returns an empty value).
Based on my particular environment I have tried /data/gitea/templates/custom/myfile.css, but the link returns a 404 response. What path do I need to use?