Add all-contributors bot

[HeidiSeibold]

Description

I think it would be nice to show who is helping this project succeed :rocket: :nerd_face:

For this we are planning to add all-contributors bots to the OpenML repositories (for more details see https://github.com/openml/OpenML/issues/1061).

What do you think? :thinking:

[PGijsbers]

It looks like the App was installed organisation wide (by @prabhant ). I think we just need to add a bot configuration (see also the openml blog repo), and a section in the readme that shows the badges? And whoever sets this up successfully can add themselves to the list with a bot command 😄

There's no need for the person interested in setting this up to scour through the project history to add contributors of the past. We will do that (perhaps a good idea to let people add themselves/add emojis during the workshop in October) 👍

[PGijsbers]

@joaquinvanschoren added the bot, now all that is needed is to add each contributor. We have to see how much the all-contributors cli can automate this for us (it's not clear to me from the documentation). If that tool falls short I'll try to either extend it or write a script that can be used to automatically find each relevant contribution.