Feature: Submission-based channels

[khionu]

Motivation

Channels like #share and #jobs shouldn't have discussion in them in order to ensure maximum visibility of posts. Threads are great for enabling discussion without affecting visibility, but enforcing that would be nice to be done through permissions. Because we can't tell a proper post from discussion, we can gate submissions by a command

Proposed usage

#share and #jobs would become read-only, but Create Public Threads and Send Messages in Threads would be enabled.

Anyone who wants to make a submission to the channel would use a command that would post a message in the appropriate channel. The message would be accompanied by an embed that displays who made the post.

Alternatively, the submitter could provide a JSON blob that would be interpreted as a Discord Embed object. For the sake of preventing fraud, the author section will always be overwritten by us with the author of the command.

Alternatives

Instead of the proactive approach, we can require a template be followed, and if a message is posted that doesn't match the template, it can be immediately deleted with a DM sent to the individual explaining why the message was deleted.