Add create message builder example (#268)

examples/11_create_message_builder/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "11_create_message_builder"
+version = "0.1.0"
+authors = ["my name <my@email.address>"]
+
+[dependencies]
+serenity = { path = "../../" }

examples/11_create_message_builder/src/main.rs

@@ -0,0 +1,43 @@
+extern crate serenity;
+
+use serenity::model::channel::Message;
+use serenity::model::gateway::Ready;
+use serenity::prelude::*;
+use std::env;
+
+struct Handler;
+
+impl EventHandler for Handler {
+    fn message(&self, _: Context, msg: Message) {
+        if msg.content == "!hello" {
+            // The create message builder allows you to easily create embeds and messages
+            // using a builder syntax.
+            // This example will create a message that says "Hello, World!", with an embed that has
+            // a title, description, and footer.
+            if let Err(why) = msg.channel_id.send_message(|m| m
+                .content("Hello, World!")
+                .embed(|e| e
+                    .title("This is a title")
+                    .description("This is a description")
+                    .footer(|f| f
+                        .text("This is a footer")))) {
+                println!("Error sending message: {:?}", why);
+            }
+        }
+    }
+
+    fn ready(&self, _: Context, ready: Ready) {
+        println!("{} is connected!", ready.user.name);
+    }
+}
+
+fn main() {
+    // Configure the client with your Discord bot token in the environment.
+    let token = env::var("DISCORD_TOKEN")
+        .expect("Expected a token in the environment");
+    let mut client = Client::new(&token, Handler).expect("Err creating client");
+
+    if let Err(why) = client.start() {
+        println!("Client error: {:?}", why);
+    }
+}