Move collection description rendering to JSON (#6944)

* First pass, moving collection description rendering to JSON

* tsc

* docs

* refactor

* test

server/migrations/20240524234042-add-content-to-collection.js

@@ -0,0 +1,14 @@
+"use strict";
+
+module.exports = {
+  async up(queryInterface, Sequelize) {
+    await queryInterface.addColumn("collections", "content", {
+      type: Sequelize.JSONB,
+      allowNull: true,
+    });
+  },
+
+  async down(queryInterface) {
+    await queryInterface.removeColumn("collections", "content");
+  },
+};