Assembler: always add an END at the end of the output

assembler.js

@@ -181,6 +181,10 @@ function decodeInstructions(str) {
     }
   }
 
+  // Add an END at the end
+  machineCode.push('0');
+  machineCode.push('0'); 
+
   return new Uint8Array(machineCode);
 }
 

readme.md

@@ -10,7 +10,9 @@
 
 ### Features
 
-- [ ] Assembler: pad to 256 bytes, OR, to start, always add an END
+- [ ] Assembler:
+    - [x] Always add an END at the end
+    - [ ] Pad up to 256 bytes
 - [x] Add constants to assembler
 - [ ] Keypad
 - [ ] Add single-stepping 

test-programs/constants.asm

@@ -3,5 +3,4 @@
 =bar $02
 ADD =foo
 STO =bar
-STO (=bar)
-END
+STO (=bar)