message: Add doc to *_with_cwd functions
diff: @@ -105,6 +105,8 @@ pub fn cargo_home() -> io::Result<PathBuf> {
  cargo_home_with_cwd(&cwd)
  }
  +/// Returns the storage directory used by Cargo within `cwd`.
  +/// For more details, see [`cargo_home`](fn.cargo_home.html).
  pub fn cargo_home_with_cwd(cwd: &Path) -> io::Result<PathBuf> {
  match env::var_os("CARGO_HOME") {
  Some(home) if !home.is_empty() => {
  @@ -153,6 +155,8 @@ pub fn rustup_home() -> io::Result<PathBuf> {
  rustup_home_with_cwd(&cwd)
  }
  +/// Returns the storage directory used by rustup within `cwd`.
  +/// For more details, see [`rustup_home`](fn.rustup_home.html).
  pub fn rustup_home_with_cwd(cwd: &Path) -> io::Result<PathBuf> {
  match env::var_os("RUSTUP_HOME") {
  Some(home) if !home.is_empty() => {
  