Document invites type field

[Zoddo]

Invite objects have a type property that can be used to differentiate guild invites (type = 0) from group DM invites (type = 1).
Bots can be exposed to group DM invites when they are posted/provided by users.

[Jupith]

These were previously removed from a pr prior to being merged by night, #4334

[Zoddo]

Ok, I didn't find it before submitting this PR.

However, I'm wondering why this shouldn't be documented. It's a cleaner way to check the type of invite than checking if guild is null, and is less susceptible to break if another invite type is introduced in the future.

[dolfies]

FRIEND also exists as type 2 (friend invites didn't ship but you can still come across them).

[Zoddo]

As friend invites didn't ship, I expect Discord to revoke them at some point. Specifically documenting these is likely not a good idea (nor going to be accepted); you should treat them as an unknown invite type.

[Zoddo]

@night Could we get a response on this point?

I'm wondering why this shouldn't be documented. It's a cleaner way to check the type of invite than checking if guild is null, and is less susceptible to break if another invite type is introduced in the future.

If Discord has a reason for not wanting us to use it, I'd prefer to know it 😃
I'm probably not the only one tempted to use it when seeing this field.