Support Content-Description/Content-Type when uploading files.

[Mehgugs]

When uploading a file to discord it would be great if supplying a Content-Description header set the description field of the attachment object. The current system of providing a partial attachment object with the ids being repurposed as indices is clunky.

Furthermore, discord ignores the Content-Type header, choosing instead to rely on file extensions. I'm unsure why this is the case.

[advaith1]

how would this work for uploading multiple files?

[Mehgugs]

--19893b0f
Content-Disposition:form-data;name="file1";filename="file-1.txt"
Content-Description:exactly as you would expect,
Content-Type:text/plain; charset=UTF-8

Hello world!
--19893b0f
Content-Disposition:form-data;name="file2";filename="file-2.txt"
Content-Description:it to work,
Content-Type:text/plain; charset=UTF-8

Hello world!
--19893b0f
Content-Disposition:form-data;name="file3";filename="file-3.txt"
Content-Description:for multiple files.
Content-Type:text/plain; charset=UTF-8

Hello world!
--19893b0f--

[Mehgugs]

I'm assuming we'd be using the files[0] syntax if this were to be supported, but i ripped this payload from my v9 code