feat(*): document and support embeds field in message create endpoint

[castdrian]

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

The message create endpoint now supports up to 10 embeds just like the webhook endpoint, these changes reflect that addition within the typings and APIMessage#create function.

Status and versioning classification:

• This PR changes the library's interface (methods or parameters added)
• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating
• This PR includes breaking changes (methods removed or renamed, parameters moved or removed)

[ckohen]

Upstream has been merged 🚀 changes are live.

[kyranet]

Since Discord seems to plan the removal of the embed field (in favour of embeds), should we refactor the code and account for less overloads? I see this as a great opportunity to remove some conditional checks made for webhooks (and interactions).

As for the embed option, should we keep it as an alias for embeds: [embed]? Since { embed } is much nicer and shorter to write (and we already have an alias for content, so why not?).

[GoldenAngel2]

src/structures/APIMessage.js#L147 needs to be updated aswell, so this works properly.

[castdrian]

src/structures/APIMessage.js#L147 needs to be updated aswell, so this works properly.

I am aware, please refer to the initial comment in italics, I somewhat mistimed opening the PR yesterday

[castdrian]

Since Discord seems to plan the removal of the embed field (in favour of embeds), should we refactor the code and account for less overloads? I see this as a great opportunity to remove some conditional checks made for webhooks (and interactions).

As for the embed option, should we keep it as an alias for embeds: [embed]? Since { embed } is much nicer and shorter to write (and we already have an alias for content, so why not?).

Changes adressed, tested & rebased :)

[csuvajit]

src/structures/APIMessage.js#L206 needs some changes here.

[ckohen]

discord.js/src/structures/interfaces/TextBasedChannel.js

Line 73 in 9e46178

* @property {MessageEmbed|Object} [embed] An embed for the message

needs updating.

[castdrian]

TextBasedChannel.js#L73 needs updating.

Done, thank you