Add tasks for all the new languages

Task/Literals-String/Swift/literals-string.swift

@@ -0,0 +1,7 @@
+let you = "You"
+let str1 = "\(you) can insert variables into strings."
+let str2 = "Swift also supports unicode in strings ı∫ƒ∂ß´™¡à"
+let str3 = "Swift also supports control characters \n\tLike this"
+let str4 = "'" // '
+let str5 = "\"" // "
+println(str3)