Create FUNDING.yml
Create FUNDING.yml

add NumFOCUS github sponsors button (recurring donations only)

This feature is launching today at GitHub Universe!

Also add a custom link to the nteract donation page.

More info on sponsor buttons here: https://help.github.com/en/github/building-a-strong-community/displaying-a-sponsor-button-in-your-repository

cc @captainsafia @rgbkrk
nteract/composition,nteract/composition,nteract/composition,nteract/nteract,nteract/nteract,nteract/nteract,nteract/nteract,nteract/nteract