tail/paths: Add documentation

src/uu/tail/src/paths.rs

@@ -14,18 +14,23 @@ use std::os::unix::fs::{FileTypeExt, MetadataExt};
 use std::path::{Path, PathBuf};
 use uucore::error::UResult;
 
+/// The kind of input, either a `File` or `Stdin` defining an [`Input`] .
 #[derive(Debug, Clone)]
 pub enum InputKind {
  File(PathBuf),
  Stdin,
 }
 
+/// Represent an input from the command line arguments.
+///
+/// Is composed of an [`InputKind`] and a display name.
 #[derive(Debug, Clone)]
 pub struct Input {
  kind: InputKind,
  pub display_name: String,
 }
 
+// TODO: move above Input
 pub enum Opened {
  File(File),
  Fifo(File),