Use gateway intents, add extraIntents config option

src/bot.js

@@ -1,8 +1,23 @@
 const Eris = require("eris");
 const config = require("./cfg");
 
+const intents = [
+  "directMessages", // For core functionality
+  "guildMessages", // For bot commands and mentions
+  "guilds", // For core functionality
+  "guildVoiceStates", // For member information in the thread header
+  "guildMessageTyping", // For typing indicators
+  "directMessageTyping", // For typing indicators
+
+  ...config.extraIntents, // Any extra intents added to the config
+];
+
 const bot = new Eris.Client(config.token, {
   restMode: true,
+  intents: Array.from(new Set(intents)),
 });
 
+/**
+ * @type {Eris.Client}
+ */
 module.exports = bot;

src/cfg.js

@@ -220,4 +220,7 @@ if (! configIsValid) {
 console.log("Configuration ok!");
 process.exit(0);
 
+/**
+ * @type {ModmailConfig}
+ */
 module.exports = config;

src/data/cfg.jsdoc.js

@@ -50,4 +50,5 @@
  * @property {string} [dbDir]
  * @property {object} [knex]
  * @property {string} [logDir]
+ * @property {array} [extraIntents=[]]
  */

src/data/cfg.schema.json

@@ -262,6 +262,11 @@
     "logDir": {
       "type": "string",
       "deprecationMessage": "This option is no longer used"
+    },
+
+    "extraIntents": {
+      "$ref": "#/definitions/stringArray",
+      "default": []
     }
   },
   "allOf": [