title: How to find code source of scipy.special.rel_entr function?
body: <p>I am trying to look for the code source of <a href="https://docs.scipy.org/doc/scipy/reference/generated/scipy.special.rel_entr.html#scipy.special.rel_entr" rel="nofollow noreferrer"><code>scipy.special.rel_entr</code></a> function in <a href="https://github.com/scipy/scipy" rel="nofollow noreferrer">GitHub Repo</a> but could not find <code>rel_entr</code> function definition.</p>
  <p>I also tried to look in this code: <a href="https://github.com/scipy/scipy/pull/6522/files#diff-0" rel="nofollow noreferrer">https://github.com/scipy/scipy/pull/6522/files#diff-0</a></p>