Minor doc update.

Author: Ruben Nine

FilestackSDK/Public/Protocols/Uploadable.swift

@@ -10,7 +10,7 @@ import Foundation
 
 /// The protocol any uploadables must conform to.
 public protocol Uploadable {
-    /// The fileName of this uploadable, or `nil` if unavailable.
+    /// The filename of this uploadable, or `nil` if unavailable.
     var filename: String? { get }
     /// The size of this uploadable in bytes, or `nil` if unavailable.
     var size: UInt64? { get }