Add completion for yash

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

README.md

@@ -34,9 +34,9 @@ Then, run as `root`:
 As usual, you can customize the destination with `DESTDIR` and `prefix`.
 
 If you want the tab completion in `bash`, you have to do it manually for now.
-Luckily, it's super easy! Just download the file [argz.sh](argz/argz.sh) and then:
+Luckily, it's super easy! Just download the file [argz.bash](argz/comp/argz.bash) and then:
 
-    $ . argz.sh
+    $ . argz.bash
     $ complete -F _argz secret
 
 It's exactly the same for `zsh` if you have enabled `bashcompinit'.

argz/comp/argz.yash

@@ -0,0 +1,11 @@
+function completion/argz {
+	typeset opts
+	opts="$($WORDS help 2>/dev/null | awk '{print $1}')"
+	case "$opts" in
+		'') ;;
+		CMD) complete -c;;
+		DIR) complete -d;;
+		FILE) complete -f;;
+		*) complete -- $opts
+	esac
+}