Xcode plugins post

@lucholaf 

I think I would jump right into the value you are going to provide:

> But not everything is bad news: while not official, you can extend Xcode through plugins. There is already great information online on how to get started - but due to the unofficial nature of plugins you'll have to piece together information from many places before getting the full picture. I've already done this myself and I'll save you the time, I've compiled a list of simple tips, tricks, and how-to's to demystify Xcode plugins and get you started quickly.