Add Swift Library

Author: SandroMachado

bip-0021.mediawiki

@@ -124,4 +124,5 @@ Characters must be URI encoded properly.
 
 === Libraries ===
 * Javascript - https://github.com/bitcoinjs/bip21
-* [[BitcoinPaymentURI|https://github.com/SandroMachado/BitcoinPaymentURI]] Java library to process and generate Bitcoin payment URI's.
+* Java - https://github.com/SandroMachado/BitcoinPaymentURI
+* Swift - https://github.com/SandroMachado/BitcoinPaymentURISwift