Add comments to pingpong.js

examples/pingpong.js

@@ -1,10 +1,26 @@
+/*
+ * A basic bot that shows how to connect to a Discord account,
+ * how to listen to messages and how to send messages.
+ *
+ * This bot responds to every "ping" message with a "pong".
+ */
+
 var Discord = require( "discord.js" );
+
+// Create the bot
 var myBot = new Discord.Client();
 
+// Login with an example email and password
 myBot.login( "hello@example.com", "password1" );
 
+// Add a listener to the "message" event, which triggers upon receiving
+// any message
 myBot.on( "message", function( message ) {
+	// message.content accesses the content of the message as a string.
+	// If it is equal to "ping", then the bot should respond with "pong".
 	if ( message.content === "ping" ) {
+		// Send a message ("pong") to the channel the message was sent in,
+		// which is accessed by message.channel.
 		this.sendMessage( message.channel, "pong" );
 	}
 } );