Remove example binaries from products (#1303)

Motivation:

Avoid examples being build when using as library.
Address #1217

Modifications:

Remove example binaries from products.
Update example section in README, show how to run them.

Result:

Examples are not being built when running `swift build`

Package.swift

@@ -82,19 +82,6 @@ var targets: [PackageDescription.Target] = [
 let package = Package(
     name: "swift-nio",
     products: [
-        .executable(name: "NIOEchoServer", targets: ["NIOEchoServer"]),
-        .executable(name: "NIOEchoClient", targets: ["NIOEchoClient"]),
-        .executable(name: "NIOChatServer", targets: ["NIOChatServer"]),
-        .executable(name: "NIOChatClient", targets: ["NIOChatClient"]),
-        .executable(name: "NIOHTTP1Server", targets: ["NIOHTTP1Server"]),
-        .executable(name: "NIOHTTP1Client", targets: ["NIOHTTP1Client"]),
-        .executable(name: "NIOWebSocketServer", targets: ["NIOWebSocketServer"]),
-        .executable(name: "NIOWebSocketClient", targets: ["NIOWebSocketClient"]),
-        .executable(name: "NIOPerformanceTester",
-                    targets: ["NIOPerformanceTester"]),
-        .executable(name: "NIOMulticastChat", targets: ["NIOMulticastChat"]),
-        .executable(name: "NIOUDPEchoServer", targets: ["NIOUDPEchoServer"]),
-        .executable(name: "NIOUDPEchoClient", targets: ["NIOUDPEchoClient"]),
         .library(name: "NIO", targets: ["NIO"]),
         .library(name: "_NIO1APIShims", targets: ["_NIO1APIShims"]),
         .library(name: "NIOTLS", targets: ["NIOTLS"]),

README.md

@@ -168,6 +168,18 @@ There are currently several example projects that demonstrate how to use SwiftNI
 - **WebSocket client** https://github.com/apple/swift-nio/tree/master/Sources/NIOWebSocketClient
 - **WebSocket server** https://github.com/apple/swift-nio/tree/master/Sources/NIOWebSocketServer
 
+To build & run them, run following command, replace TARGET_NAME with the folder name under `./Sources`
+
+```bash
+swift run TARGET_NAME
+```
+
+For example, to run NIOHTTP1Server, run following command:
+
+```bash
+swift run NIOHTTP1Server
+```
+
 ## Getting Started
 
 SwiftNIO primarily uses [SwiftPM](https://swift.org/package-manager/) as its build tool, so we recommend using that as well. If you want to depend on SwiftNIO in your own project, it's as simple as adding a `dependencies` clause to your `Package.swift`: