feat(GuildManager): add AFK and system channel options in create (#4837)

This commit adds support for the `afk_channel_id`, `afk_timeout`, and
`system_channel_id` parameters in the
[create guild](https://discord.com/developers/docs/resources/guild#create-guild-json-params)
endpoint by adding the `afkChannelID`, `afkTimeout`, and
`systemChannelID` options in `GuildManager#create`.

This commit also fixes a minor bug in `create` when specifying types for
the channels due to the channel types not being changed from `'text'`,
`'voice'` etc to the corresponding numbers, so Discord would return an
error.

typings/index.d.ts

@@ -1941,10 +1941,7 @@ declare module 'discord.js' {
 
   export class GuildManager extends BaseManager<Snowflake, Guild, GuildResolvable> {
     constructor(client: Client, iterable?: Iterable<any>);
-    public create(
-      name: string,
-      options?: { region?: string; icon: BufferResolvable | Base64Resolvable | null },
-    ): Promise<Guild>;
+    public create(name: string, options?: GuildCreateOptions): Promise<Guild>;
     public fetch(id: Snowflake, cache?: boolean, force?: boolean): Promise<Guild>;
   }
 
@@ -2577,6 +2574,19 @@ declare module 'discord.js' {
     name?: string;
   }
 
+  interface GuildCreateOptions {
+    afkChannelID?: number;
+    afkTimeout?: number;
+    channels?: PartialChannelData[];
+    defaultMessageNotifications?: DefaultMessageNotifications | number;
+    explicitContentFilter?: ExplicitContentFilterLevel | number;
+    icon?: BufferResolvable | Base64Resolvable | null;
+    region?: string;
+    roles?: PartialRoleData[];
+    systemChannelID?: number;
+    verificationLevel?: VerificationLevel | number;
+  }
+
   interface GuildWidget {
     enabled: boolean;
     channel: GuildChannel | null;