TS attachment required fields #277

Airtable documentation:

When creating an attachment, url is required, and filename is optional.

Attachment interface:

export interface Attachment {
    id: string;
    url: string;
    filename: string;
    size: number;
    type: string;
    thumbnails?: {
        small: Thumbnail;
        large: Thumbnail;
        full: Thumbnail;
    };
}

filename, size, type etc. not so optional.

Please do props optional or split type for different actions (create/update/delete).