Added AsyncSequenceReaderError

Author: dimitribouniol

Sources/AsyncSequenceReader/AsyncSequenceReaderError.swift

@@ -0,0 +1,13 @@
+//
+//  AsyncSequenceReaderError.swift
+//  AsyncSequenceReader
+//
+//  Created by Dimitri Bouniol on 2021-11-17.
+//  Copyright © 2021 Mochi Development, Inc. All rights reserved.
+//
+
+/// An Async Sequence Reader Error.
+public enum AsyncSequenceReaderError: Error {
+    /// Not enough elements were available to read (ie. `actual < minimum`)
+    case insufficientElements(minimum: Int, actual: Int)
+}