title: How to create source tarball release of package with npm without publishing it
body: <p>I want to make source tarball release of npm package without publishing it, something similar as in python:</p>
  
  <p><code>python setup.py sdist</code></p>
  
  <p>I want to also specify which files to include, something similar like <code>MANIFEST.in</code> file in python.</p>
  
  <p>I know i can publish package to npm and that creates tarball, but this is my private project and i don't want to have it published.</p>