add channel categories (#1727)

* add channel categories

* add specific class

* speed

* Update Channel.js

* fix type typo

* Update Channel.js

* rewrite position stuff in prep for category sorting

* fix small issues in generation of permissions

* Update Guild.js

* Update Constants.js

* Update GuildChannel.js

* doc fix

* Update GuildChannel.js

* <.<

src/util/Constants.js

@@ -165,13 +165,6 @@ exports.VoiceStatus = {
   DISCONNECTED: 4,
 };
 
-exports.ChannelTypes = {
-  TEXT: 0,
-  DM: 1,
-  VOICE: 2,
-  GROUP: 3,
-};
-
 exports.OPCodes = {
   DISPATCH: 0,
   HEARTBEAT: 1,
@@ -574,6 +567,14 @@ exports.UserFlags = {
   HYPESQUAD: 1 << 2,
 };
 
+exports.ChannelTypes = {
+  TEXT: 0,
+  DM: 1,
+  VOICE: 2,
+  GROUP: 3,
+  CATEGORY: 4,
+};
+
 exports.ClientApplicationAssetTypes = {
   SMALL: 1,
   BIG: 2,