Seeking channels-ui repository

[tomadelaney]

I'd like to branch the channels-ui repo in order to make it compatible with the latest Polaris build

in order to support an app which uses the Marketplace Kit pattern.

Though there is still a documentation (shopify/channels-ui-docs),  the original repo seems to be missing.

Does anybody know where I can find this old repo(shopify/channels-ui) so that I can either fork or clone it?