Add Swift to ReadMe
Add Swift to ReadMe

PR #14 added Swift Support, but did not update the supported languages
bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator,bafolts/plantuml-code-generator