Use `PlatformSupport.makeEventLoopGroup` on BasicTutorial (#1179)

Sources/Examples/RouteGuide/Client/main.swift

@@ -201,7 +201,7 @@ struct RouteGuide: ParsableCommand {
     // Load the features.
     let features = try loadFeatures()
 
-    let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+    let group = PlatformSupport.makeEventLoopGroup(loopCount: 1)
     defer {
       try? group.syncShutdownGracefully()
     }

docs/basic-tutorial.md

@@ -473,7 +473,7 @@ use the `insecure` builder and specify the server address and port we want to
 connect to:
 
 ```swift
-let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+let group = PlatformSupport.makeEventLoopGroup(loopCount: 1)
 defer {
   try? group.syncShutdownGracefully()
 }