Instant messaging for the community?



I manage a website that host translations and articles of members of my community.
Slack edit is exactly what I need: realtime collaboration for markdown (easy to use and no risk of conflict), support for folder structure (the website could keep the same strucure).

I’d like to self-host stack-edit but I really don’t know anything.
That’s why having an instant messaging service would really help me…
Does a such thing exists ?

Thanks in advance !!