implemented Incfsz Instruction (#14)

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#14

de/darkress/pic16f84sim/decoder/CommandDecoder.java

@@ -21,8 +21,7 @@ public class CommandDecoder
             case 0xA00:
                 return new Incf(input);
             case 0xF00:
-                //incfsz();
-                break;
+                return new Incfsz(input);
             case 0x400:
                 //iorwf();
                 break;