Hi RStudio Community,
I made a custom template for pkgdown that is focused on improving the accessiblity and readabilty of the documentation. It offers two themes for your website, light and dark, and improves the overall reading experience of the articles by applying minor patches to the CSS.
It’s called preferably and you can find it on GitHub, and see an example here.
It’s super easy to setup. You only need to install the package and set your template on your _pkgdown.yml to preferably. Read more here.
Please feel free to contact me if you have any questions, or if you happen to find any bugs or have any suggestions! 
PS. I've checked the roles and couldn't find anything against posting this here, so, I hope it's ok. I also thought this might be helpful for people looking for alternative pkgdown templates, e.g., here or here.