feat: Guild Forum channel

https://github.com/discordjs/discord.js/pull/8651

src/util/ChannelFlags.js

@@ -0,0 +1,45 @@
+'use strict';
+
+const BitField = require('./BitField');
+
+/**
+ * Data structure that makes it easy to interact with a {@link BaseChannel#flags} bitfield.
+ * @extends {BitField}
+ */
+class ChannelFlags extends BitField {}
+
+/**
+ * Numeric guild channel flags. All available properties:
+ * * `PINNED`
+ * * `REQUIRE_TAG`
+ * @type {Object}
+ * @see {@link https://discord.com/developers/docs/resources/channel#channel-object-channel-flags}
+ */
+ChannelFlags.FLAGS = {
+  PINNED: 1 << 1,
+  REQUIRE_TAG: 1 << 4,
+};
+
+/**
+ * @name ChannelFlags
+ * @kind constructor
+ * @memberof ChannelFlags
+ * @param {BitFieldResolvable} [bits=0] Bit(s) to read from
+ */
+
+/**
+ * Bitfield of the packed bits
+ * @type {number}
+ * @name ChannelFlags#bitfield
+ */
+
+/**
+ * Data that can be resolved to give a channel flag bitfield. This can be:
+ * * A string (see {@link ChannelFlags.FLAGS})
+ * * A channel flag
+ * * An instance of ChannelFlags
+ * * An Array of ChannelFlags
+ * @typedef {string|number|ChannelFlags|ChannelFlagsResolvable[]} ChannelFlagsResolvable
+ */
+
+module.exports = ChannelFlags;