Adds a dummy .R file that will prompt roxygen to generate basic
package-level documentation. If your package is named "foo", this will make
help available to the user via ?foo or package?foo. Once you call
devtools::document(), roxygen will flesh out the .Rd file using data from
the DESCRIPTION. That ensures you don't need to repeat the same information
in multiple places. This .R file is also a good place for roxygen
directives that apply to the whole package (vs. a specific function), such as
global namespace tags like @importFrom.
use_package_doc()The documentation chapter of R Packages