Remove mention of LambdaCodableAdapter being a class and update code blocks

Author: aryan-25

Sources/AWSLambdaRuntimeCore/Documentation.docc/Proposals/0001-v2-api.md

@@ -164,9 +164,9 @@ try await serviceGroup.run()
 
 A detailed explanation is provided in the **Codable Support** section. In short, much of the boilerplate code defined for
 each handler protocol in `Lambda+Codable` and `Lambda+String` will be replaced with a single `LambdaCodableAdapter`
-class.
+struct.
 
-This adapter class is generic over (1) any handler conforming to `LambdaHandler`, (2) the user-specified input and
+This adapter struct is generic over (1) any handler conforming to `LambdaHandler`, (2) the user-specified input and
 output types, and (3) any decoder and encoder conforming to `LambdaEventDecoder` and `LambdaOutputDecoder`. The adapter
 will wrap the underlying handler with encoding/decoding logic.
 
@@ -424,14 +424,14 @@ public protocol LambdaHandler {
 
 ```swift
 public protocol LambdaEventDecoder {
-    /// Decode the ByteBuffer representing the received event into the generic type T
+    /// Decode the ByteBuffer representing the received event into the generic type Event
     /// the handler will receive
-    func decode<T: Decodable>(_ type: T.Type, from buffer: ByteBuffer) throws -> T
+    func decode<Event: Decodable>(_ type: Event.Type, from buffer: ByteBuffer) throws -> Event
 }
 
 public protocol LambdaOutputEncoder {
-    /// Encode the generic type T the handler has produced into a ByteBuffer
-    func encode<T: Encodable>(_ value: T, into buffer: inout ByteBuffer) throws
+    /// Encode the generic type Output the handler has produced into a ByteBuffer
+    func encode<Output: Encodable>(_ value: Output, into buffer: inout ByteBuffer) throws
 }
 ```
 
@@ -498,7 +498,7 @@ or `Void`.
 ```swift
 public struct ClosureHandler<Event, Output>: LambdaHandler {
     /// Initialize with a closure handler over generic Input and Output types
-    public init(body: @escaping (Event, LambdaContext) async throws -> Output) where Output: Encoda
+    public init(body: @escaping (Event, LambdaContext) async throws -> Output) where Output: Encodable
     /// Initialize with a closure handler over a generic Input type (Void Output).
     public init(body: @escaping (Event, LambdaContext) async throws -> Void) where Output == Void
     /// The business logic of the Lambda function.