Copying an R script to PATH when installing a package (like setuptools in Python)

Question

Consider this script in R that can be called from command line as ./add.R 1 2 to add two numbers:

Content of add.R (do chmod +x add.R to make it executable):

#!/usr/bin/env Rscript

'usage: add.r <a> <b>' -> doc

suppressMessages(library(docopt))

opts <- docopt(doc)

print(as.double(opts[["a"]]) + as.double(opts[["b"]]))

Is there any way to bundle add.R in an R package and have the installation process copy this script to PATH (or update PATH) and make it available for general use? That is, I should be able to do add.R 1 2 from anywhere.

In Python, setuptools lets you do this using scripts or console_scripts.