The idea is simple, I hope.
Through the discord console channel, if enabled in settings, you can upload a plugin to the main server and should you have a plugin manager installed you can quickly enable the said plugin.

However, it would be nice if you could upload a .zip file, with the plugin say DiscordSRV.jar and its config folder DiscordSRV/

Closing this as this feature no longer exists.

Console plugin uploading is a very unsupported (and insecure) feature, the chances of this seeing the light of day are slim

Thank you for letting me know 😄