Add icon to navigation tree #17
Description
Icon on the first item of the navigation tree is missing
In the ZIM
Online
DevDocs compiles these into a spritesheet that has a nondeterministic name so it's not easy to pull just the icon we want out, but it might be possible to grab the whole sheet. The icons are also available in the DevDocs repo: https://github.com/freeCodeCamp/devdocs/tree/main/public/icons/docs, but there's no license information for the icons which may differ from the content.