Add the link to our Discord

[exitflynn]

Discord's our primary means of communication which the site currently has zero mention of. We usually share https://osdc.dev/ for Community Partner purposes like recently with FOSSConf '23 and it's a major issue if people aren't able to join the community.
The proposed solution for now is to link to the discord here, before any other socials imo. A working link can be found at https://osdc.dev/links.