Shared styleguides

This version supports shared styleguides which where added this summer (requested in #1 and #2)
Also, I've fixed an issue where textStyles's attributes property didn't have a return statement if there was no textStyles.

0.3.0

• Added an option to choose between UIKit or AppKit in snippets.
• Text layers now provide a swift snippet.

0.2.3

Fixed issue where the font weight didn't use the correct values.

0.2.2

• When a textStyle uses a SFPro font, the system font calls are now used.
  Ex: UIFont(name: "SFProDisplay-Regular", ofSize: 18) is now replaced by UIFont.systemFont(ofSize: 18, weight: 500).

• Fixed an issue with the Color typealias not being accessible.

macOS support improvements

Generated code now correctly uses either UIKit or AppKit.

Color formats

• Colors declaration can now use 3 different formats: rgb, hex rgba or hex argb.
• Improved the way the custom color struct name is handled.

The Beginning

0.1.0

Updated build files