updated AudioUnitViewController initializers for medium blog article about How To Create Audio Unit From Scratch

AudioUnitViewController.swift

// this initializer is called by NSExtensionContextVendor beginRequestWithExtensionItems,
    // without it Garage Band will not show the UI!
    init() {
        super.init(nibName: "AudioUnitViewController", bundle: Bundle(for: AudioUnitViewController.self))
    }
    
    override public init(nibName nibNameOrNil: NSNib.Name?, bundle nibBundleOrNil: Bundle?) {
        super.init(nibName: "AudioUnitViewController", bundle: Bundle(for: AudioUnitViewController.self))
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }