[Feature request] Add multiple users at once

Is your feature request related to a problem? Please describe.

I am trying to attribute multiple users with the same attributes, but I can't seem to attribute more than 1 user at a time Reference

Describe the solution you'd like

I would like to be able to add multiple users for the same contributions in a single pull request.

Describe alternatives you've considered

I don't know of any alternatives.

Additional context

I set up a little sandbox to test this, but it didn't work: seanpm2001/All-Contributors_Test_Site#1