Black and white icon

[musoke]

Thank you for this package! It simplifies things significantly.

ORCID's brand guidelines say

For print, use of the ORCID iD icon in addition to the iD URI is encouraged, though remains at the discretion of the publisher, and a black and white iD icon may also be used where appropriate.

It would be nice if this package included a black and white version of the logo in addition to the typical green.