If it should be the sort of thing that belongs on this page, you could add a section in 'General' on the Conlang Database Project, currently being planned and organised. The main location to link to is probably our planning document, it has links to everything else: https://docs.google.com/document/d/1y5QhCZpn3XcaosbP3wAEtoNGluLHHLzvateNZNAI6Ek/. We would like to attract more people to take part in making decisions and compiling the database. Assuming it happens it will be a subdomain of the LCS website, like CALS which has its own entry here.
TBH there are quite a few more conlang Facebook groups than the one named, it's up to you how many you're prepared to include in 'Social Media' but these are the ones I know: