implemented Nop Instruction

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#10

de/darkress/pic16f84sim/commands/Nop.java

@@ -0,0 +1,14 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Nop extends LiteralCommandUtils implements Command
+{
+
+    @Override
+    public void execute()
+    {
+        // Do nothing, just increment the PC
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/decoder/CommandDecoder.java

@@ -111,7 +111,7 @@ public class CommandDecoder
 
         if ((input | 0x0060) == 0x0060)
         {
-            //nop();
+            return new Nop();
         }
 
         if (input == 0x0064)