Adding plain old Ruby example

examples/por.rb

@@ -0,0 +1,17 @@
+require 'sidekiq'
+
+# Start up sidekiq via
+# ./bin/sidekiq -r ./examples/por.rb
+# and then you can open up an IRB session like so:
+# irb -r ./examples/por.rb
+# where you can then say
+# PlainOldRuby.perform_async "like a dog", 3
+#
+class PlainOldRuby
+  include Sidekiq::Worker
+
+  def perform(how_hard="super hard", how_long=1)
+    sleep how_long
+    puts "Workin' #{how_hard}"
+  end
+end