test.R

#' My roxy
#' 
#' This is an example of how you would use roxygen.
#' 
#' ```{r}
#' #' Test example
#' #' 
#' #' This is an example. Here is how you embed R code:
#' #' 
#' #' ```{r}
#' #' sessionInfo()
#' #' ```
#' #' 
#' #' @export
#' #' @param foo this is a parameter
#' test <- function(foo){
#'   foo^2
#' }
#' ```
#' 
#' @export
#' @param args some parameters
myroxy <- function(args){
  
}

Formatted page seems fine:

myroxy                package:roxygen2                 R Documentation

My roxy

Description:

     This is an example of how you would use roxygen.

Usage:

     myroxy(args)

Arguments:

    args: some parameters

Details:

     #' Test example
     #'
     #' This is an example. Here is how you embed R code:
     #'
     #' ```{r}
     #' sessionInfo()
     #' ```
     #'
     #' @export
     #' @param foo this is a parameter
     test <- function(foo){
       foo^2
     }

OK very impressive :)