

One problem with that use case is that you as the creator doesn’t control where (screen position) and how (font face, size, etc) the subtitles are rendered. The browser and user control that, so I doubt they would be widely used for meme because of this.
However, I do agree that it would be nice to have support for it for other reasons.
Or if you want some basic configuration, like user management and repo creation. Use something lightweight like gitolite