Add gnu wc wrapper (#625)

Wasn't quite sure where to place this, if anyone has a better place for
it please let me know. It's a nice wrapper around the gnu `wc` command
that gives you named columns back. Nice imo, since I always forget which
number means which.

modules/wc/wc.nu

@@ -0,0 +1,9 @@
+export def main [...rest] {
+  let stdin = $in
+  if ($rest | length ) > 0 {
+    ^wc $rest | lines | parse -r '^\s*(?<lines>\d+)\s*(?<words>\d+)\s*(?<bytes>\d+)\s*(?<file>.*)$' 
+  } else {
+    $stdin | ^wc | lines | parse -r '^\s*(?<lines>\d+)\s*(?<words>\d+)\s*(?<bytes>\d+)\s*$' 
+    
+  }
+}