title: Type 'xxx' does not conform to protocol 'Encodable'
body: <p>I'm not sure what to do here, previous errors told me to make this struct encodable but I'm not sure how exactly how to do it? ChatMessage works but ImageMessage does not. The specific error is <code>Type 'ImageMessage' does not conform to protocol 'Encodable'</code></p>
  <pre><code>import Foundation
  import FirebaseFirestoreSwift
  import UIKit
  
  struct ChatMessage: Codable, Identifiable {
      @DocumentID var id: String?
      let fromId, toId, text: String
      let timestamp: Date
  }
  
  struct ImageMessage: Encodable, Identifiable {
      @DocumentID var id: String?
      let fromId, toId: String
      let image: UIImage
      let timestamp: Date
  }```
  </code></pre>