Add failing test.

doc/Emitting.markdown

@@ -168,6 +168,22 @@ Copy command: immediate -> word
     = .data
     = .space position 2
 
+Copy command: byte-sized immediate -> word
+
+    | reserve word position
+    | routine main {
+    |     copy #1 position
+    | }
+    = main:
+    =   lda #1
+    =   sta position
+    =   lda #0
+    =   sta position+1
+    =   rts
+    = 
+    = .data
+    = .space position 2
+
 Copy command: word -> word
 
     | reserve word position1