Ecosystem defolkloring: add support channel information

[adamczykm]

This issue is being generated by script to prompt maintainers to add
links to support channels (such as slack channels, discord channels, or other chats).

It is accompanied by a draft PR appending a placeholder section to the repository's
README.

In the event that a repository has a private or invite-only support channel
(such as a private slack or discord), we ask that you at least indicate the
existence of such a channel so that non-members can be aware of teammates who
may have access to these channels.