Added swapf Instruction (#23)

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#23

de/darkress/pic16f84sim/commands/Decfsz.java

@@ -26,7 +26,7 @@ public class Decfsz extends FileRegisterCommandUtils implements Command
         if((result % 256) == 0)
         {
             Nop nop = new Nop();
-            nop.execute();
+            nop.execute(); // TODO: What happens if an interrupt gets triggered during the nop execution?
         }
         ProgramCounter.incPC();
     }