fork.sh's theme component to add the site name next to the icon

• It respects the scroll-replacement within topics and PMs
• It uses no JavaScript, so it shouldn't make Discourse any slower or break on updates
• It also looks pretty good (IMO)
• It's actual text, instead of part of the image
• Here's how to install it.
• You're supposed to add it as a child theme, and not make it "enabled by default" or "selectable by users". It's a theme component, not a whole theme.