[xattr] missing spec #941

Sanity checks

• My issue relates to a specific CLI completion spec (e.g. git checkout is missing options in git completion spec). If your issue is more general, please create your issue here: withfig/fig
• I have searched github.com/withfig/autocomplete/issues and there are no duplicates of my issue
• I would like to work on this.

What CLI tool does this relate to?

xattr

Which statement makes the most sense?

This completion spec does not exist

Issue Details

See https://keith.github.io/xcode-man-pages/xattr.1.html