There isn't a guide specifically for NodeBB, but you could follow this guide and use this page to find out how to get your certificate signed.
Hm... are you using a special theme?
So what would this page you're proposing look like? How would it work?
@CyanPrime not sure how that's fixed it as your route inside theme.less doesn't actually point to the vanilla template. For that file to point at vanilla, you'd be looking at ../../../nodebb-theme-vanilla, but if it works then, so be it.
Should have posted this under fake account @Lulian-Jam maybe you could have won!