R object documentation: Package documentation as first item

I have an R package and I want to display the general information about the package as first item in the created PDF manual.

I use roxygen2 (version 7.0.2) for creating the documentation and followed the instructions given here. When I create the documentation, the items appearing in the manual are all ordered alphabetically, including the item for the general documentation. But, of course, I want to have the general documentation at the top.

It seems that putting the package documentation item first must work somehow because it works in the manual of knitr.

My setup: I created a package "TestPackage" using RStudio, with one "hello.R" file:

#' Hello world function
#'
#' Prints "Hello, world!"
#'
#'@return nothing interesting
hello <- function() {
  print("Hello, world!")
}

and one "TestPackage.R" file with the general documentation for the package.

#' A test package
#'
#' @docType package
#' @name TestPackage
NULL

When I run,

R CMD Rd2pdf TestPackage

I get a PDF manual with the first item "hello" and then the item "TestPackage".

How can I achive that the item for the package comes first?