The last year has been admittedly extraordinary, but even prior to COVID-19 successful professionals needed to cultivate social skills for online interaction. Last August, COLI developed some guidelines for students interacting within courses, be it via asynchronous discussion, Zoom (web conferencing) or any other mode. You can simply drop the link into your syllabus, or perhaps borrow the language and modify it as you need to.
COLI is also interested to hear what suggestions you may have to improve this resource.