To enable, you need to use the right name for the directory inside Themes. For instance, you can do this at the root directory of your Known instance:
git submodule add https://github.com/hugoroy/knownTheme.git Themes/Hugoroy
You can also edit css/fonts.less and add your own webfont, pointing to your local files. (This might help you: https://google-webfonts-helper.herokuapp.com/fonts/roboto?subsets=latin,latin-ext)
- enable attribution for backgroud picture