Refactor to more consistent structure (e.g. "plugins")

plugins/nag/unnag.ts

@@ -0,0 +1,25 @@
+import {
+	type ChatInputCommandInteraction,
+	SlashCommandBuilder,
+} from 'discord.js';
+import type {Settings} from '../../plugin';
+import {Nag} from './models';
+
+export default function (_settings: Settings) {
+	return {
+		data: new SlashCommandBuilder()
+			.setName('unnag')
+			.setDescription('Remove a nag'),
+		execute: async (interaction: ChatInputCommandInteraction) => {
+			// Find all nags for this user and delete them.
+			// TODO In the future, we should support having multiple nags
+			const results = await Nag.findAll({
+				where: {userId: interaction.user.id},
+			});
+			for (const result of results) {
+				await result.destroy();
+			}
+			return;
+		},
+	};
+}