Get the default notes reference for a repository
Examples
if (FALSE) { # \dontrun{
## Create and initialize a repository in a temporary directory
path <- tempfile(pattern="git2r-")
dir.create(path)
repo <- init(path)
config(repo, user.name = "Alice", user.email = "alice@example.org")
## View default notes reference
note_default_ref(repo)
} # }