added documentation

AmplifyPlugins/Core/AWSPluginsCore/Auth/AuthAWSCredentialsProvider.swift

@@ -35,16 +35,42 @@ public protocol AWSCredentialsProvider {
     func fetchAWSCredentials() async throws -> AWSCredentials
 }
 
-public protocol AWSTemporaryCredentials: AWSCredentials {
-
-    var sessionToken: String { get }
+/**
+ Represents AWS credentials.
 
-    var expiration: Date { get }
-}
+ Typically refers to long-term credentials that do not expire unless manually rotated or deactivated.
+ These credentials are generally associated with an IAM (Identity and Access Management) user and are used to authenticate API requests to AWS services.
 
+ - Properties:
+ - accessKeyId: A unique identifier.
+ - secretAccessKey: A secret key used to sign requests cryptographically.
+ */
 public protocol AWSCredentials {
 
+    /// A unique identifier.
     var accessKeyId: String { get }
 
+    /// A secret key used to sign requests cryptographically.
     var secretAccessKey: String { get }
 }
+
+/**
+ Represents temporary AWS credentials.
+
+ Refers to short-term credentials generated by AWS STS (Security Token Service).
+ These credentials are used for temporary access, often for applications, temporary roles, federated users, or scenarios requiring limited-time access.
+
+ - Inherits: AWSCredentials
+
+ - Properties:
+ - sessionToken: A token that is required when using temporary security credentials to sign requests.
+ - expiration: The expiration date and time of the temporary credentials.
+ */
+public protocol AWSTemporaryCredentials: AWSCredentials {
+
+    /// A token that is required when using temporary security credentials to sign requests.
+    var sessionToken: String { get }
+
+    /// The expiration date and time of the temporary credentials.
+    var expiration: Date { get }
+}