Add udp example.

Author: ioquatix

examples/udp.rb

@@ -0,0 +1,26 @@
+#!/usr/bin/env ruby
+
+require 'async'
+require_relative '../lib/async/io'
+
+endpoint = Async::IO::Endpoint.udp("localhost", 5300)
+
+Async do |task|
+	endpoint.bind do |socket|
+		# This block executes for both IPv4 and IPv6 UDP sockets:
+		loop do
+			data, address = socket.recvfrom(1024)
+			pp data
+			pp address
+		end
+	end
+	
+	# This will try connecting to all addresses and yield for the first one that successfully connects:
+	endpoint.connect do |socket|
+		loop do
+			task.sleep rand(1..10)
+			socket.send "Hello World!", 0
+		end
+	end
+end
+