Obvious things like project name, version, homepage
Some sort of fast overview of the project with a "1 click way to get almost anywhere".
Maybe (easy) "most referenced classes/funcs/etc"
Maybe (hard) a 2D map representation of everything in the project?
E.g. big (huge) rect formed by horizontal modules, divided into vertical module members,
divided into horizontal class/struct members, etc.
Maybe even not horizontal modules, but rectangles with areas based on the content inside
Inspiration: FileLight