Add info about connecting modules from objc to swift

[iSevenDays]

For example we have ImageGalleryStory as a name of our module.

Then

ImageGalleryStoryViewController.swift

class ImageGalleryStoryViewController : UIViewController, ImageGalleryStoryViewInput

var output: ImageGalleryStoryViewOutput!

must be

@objc var output: ImageGalleryStoryViewOutput!

and

protocol ImageGalleryStoryViewOutput

must be

@objc protocol ImageGalleryStoryViewOutput

Or else -moduleInput is not callable from objective c.

[etolstoy]

Hi, @iSevenDays. We'll add this information to one of our planned swift articles!

[iSevenDays]

Thanks!