feat: add animated banner guild feature

[iShibi]

Please describe the changes this PR makes and why it should be merged:

• Document animated guild banners discord/discord-api-docs#3948

Status and versioning classification:

[Jiralite]

This should instead be modified in the AnonymousGuild class:

discord.js/packages/discord.js/src/structures/AnonymousGuild.js

Lines 69 to 76 in ed0cfd9

	/**
	* The URL to this guild's banner.
	* @param {StaticImageURLOptions} [options={}] Options for the Image URL
	* @returns {?string}
	*/
	bannerURL({ format, size } = {}) {
	return this.banner && this.client.rest.cdn.Banner(this.id, this.banner, format, size);
	}

Both an InviteGuild and a Guild can receive the animated hash.

[Jiralite]

Upstream got merged. Are you able to continue, @iShibi?

[iShibi]

Upstream got merged. Are you able to continue, @iShibi?

it's been a long gap, you can takeover if it's fine with you

[Jiralite]

I've looked over what needs to be done to support animated guild banners in discord.js.

For some reason, the AnonymousGuild's bannerURL() method already supports dynamic hashes:

discord.js/packages/discord.js/src/structures/AnonymousGuild.js

Lines 78 to 85 in 402514f

	/**
	* The URL to this guild's banner.
	* @param {ImageURLOptions} [options={}] Options for the image URL
	* @returns {?string}
	*/
	bannerURL(options = {}) {
	return this.banner && this.client.rest.cdn.banner(this.id, this.banner, options);
	}

discord.js/packages/discord.js/typings/index.d.ts

Line 268 in 402514f

public bannerURL(options?: ImageURLOptions): string | null;

All that's left is to bump discord-api-types to 0.31.0 so the typings are updated for the new guild feature. However, this is already being done in #7634, so it looks like no pull request is needed for this and support will naturally come!

[SpaceEEC]

See comment above ^