Some comments:

- this is my first "proper" patch so I apologize for any faux-pas :)

- in particular, I didn't quite know where to put the package, so I thought
I
would follow tradition and put it in a "language-xyz.scm" file, which is
new in
this case (the language is D)

- I didn't know what to do with the Copyright line in the new file, so I
didn't
add one

Best regards,
Hugo