While companion and package links are easy to navigate to when you know where to find them in scaladoc, many newcomers are unaware that the links exist, fail to notice the peel-over on the class icon or that the package breadcrumbs are navigable, and are constantly surprised to find the often essential documentation hidden behind these links. A simple explanation on the right hand side of the title bar in scaladoc would surely help this:

For classes/traits without companions:

Go to package docs

for classes/traits with companions:

Go to companion or package docs