Additions to source tarball

[Natureshadow]

Hi,

I am currently making mimerender available in the official Debian repositories.

While the package is fine, overall, it would be great to have the docs/ and examples/ included in the official source tarball (i.e. that on PyPI).

Please also consider pgp-signing the upload to pypi so we in Debian (and other distributions) can create a trusted build.

Thanks, Nik