I’ve worked in SEO for over 15 years and when I visit a site can’t help but look under the hood for SEO issues
Considering this part of the site is a forum the SEO isn’t too bad (some of it is good, which is rare for forums), but you have a semi-hidden link to discourse.org in the code.
View source of a topic for example and you’ll find:
> <noscript data-path="/t/using-certbot-on-a-centos-6-server-tutorial/39760">
> ... code removed ...
> <footer id='noscript-footer'>
This sort of hidden linking is greyhat SEO at best. I’ve created free WordPress themes in the past with a Powered by Link in the footer (not semi-hidden like this one) and because my themes are used on tens of thousands of sites it generated millions of backlinks. Google penalized the site so badly I had to use another domain, so you can imagine what they might do with a semi-hidden link!