Add unmaintained note to interleave.el "Commentary" section

[skangas]

As I was looking into using either this or org-noter, it would have been helpful to know this package is currently unmaintained. May I suggest to perhaps a note to this effect to the "Commentary" section so this is visible from within Emacs itself (i.e. M-x list-packages)?

Thanks for the package.

[rudolfochrist]

I guess it's the best to remove it from melpa entirely. If someone still wants to use interleave for whatever reason, she can install it manually.