fixed a typo in detach code and added it to subcommand match

src/command.rs

@@ -146,7 +146,7 @@ pub fn detach(pargs: &mut Arguments) {
 	let exists = tmux
 		.has_session()
 		.target_session(target.clone())
-		.output.unwrap();
+		.output().unwrap();
 	if !exists.success() { error::no_target(target.to_string()); }
 
 	tmux

src/main.rs

@@ -19,6 +19,9 @@ fn main() {
 		Some("a" | "attach")
 			=>	command::attach(&mut args),
 
+		Some("d" | "detach")
+			=>	command::detach(&mut args),
+
 		Some("has")
 			=>	command::has(&mut args),