title: How do I install Bash completions for my Haskell package's executable?
body: <p>The Haskell package <code>optparse-applicative</code> <a href="https://github.com/pcapriotti/optparse-applicative/wiki/Bash-Completion" rel="nofollow noreferrer">provides instructions</a> for creating a bash completion script for an executable, and then suggests that this</p>
  
  <blockquote>
    <p>should be shipped with the program and copied to the appropriate directory usually (<code>/etc/bash_completion.d/</code>) during installation.</p>
  </blockquote>
  
  <p>I wold like to ship and install this script with my package, along wit the executable. How do I instruct Cabal (in my .cabal) to </p>
  
  <ol>
  <li>include the bash completion script along with my package, and</li>
  <li>copy the script to <code>/etc/bash_completion.d/</code>?</li>
  </ol>