adding NIO.EmbeddedEventLoop to shell

Author: rafiki270

Sources/ExecutorKit/Exports.swift

@@ -8,3 +8,5 @@
 @_exported import WebErrorKit
 @_exported import protocol NIO.EventLoop
 @_exported import class NIO.EventLoopFuture
+@_exported import class NIO.EmbeddedEventLoop
+

Sources/ShellKit/Shell.swift

@@ -81,7 +81,7 @@ public class Shell: Executor {
     /// Initializer
     /// - Parameter connection: Connection details
     /// - Parameter eventLoop: Event loop
-    public init(_ connection: Connection, on eventLoop: EventLoop) throws {
+    public init(_ connection: Connection, on eventLoop: EventLoop = EmbeddedEventLoop()) throws {
         self.eventLoop = eventLoop
         switch connection.storage {
         case .local(dir: let dir):