Support for completions

build.rs

@@ -0,0 +1,18 @@
+use clap_complete::{generate_to, shells::*};
+use std::io::Error;
+
+include!("src/cli.rs");
+
+fn main() -> Result<(), Error> {
+    let outdir = "completions";
+    let app_name = "dust";
+    let mut cmd = build_cli();
+
+    generate_to(Bash, &mut cmd, app_name, outdir)?;
+    generate_to(Zsh, &mut cmd, app_name, outdir)?;
+    generate_to(Fish, &mut cmd, app_name, outdir)?;
+    generate_to(PowerShell, &mut cmd, app_name, outdir)?;
+    generate_to(Elvish, &mut cmd, app_name, outdir)?;
+
+    Ok(())
+}