Link to Slack dead, is Slack still used?

Hi,

On https://www.postgresql.org/list/pgsql-docs/ under the "Quick links" on the left I see this link
https://postgres-slack.herokuapp.com/but that app seems to be offline.
 

Is Slack used by the PostgreSQL docs community? 
If so: can somebody please update this link?
If no: shall we remove that link?

Have a good one,

-Ni