Change bold code snippets to inline code blocks

47-06.md

@@ -51,7 +51,7 @@ potentially speeding up operations like rectangle fills by four times.
 
 And, as it turns out, four-plane parallelism works quite nicely indeed.
 Listing 47.6 is yet another rectangle-fill routine, this time using the
-Map Mask to set up to four pixels per **STOS.** The only trick to
+Map Mask to set up to four pixels per `STOS`. The only trick to
 Listing 47.6 is that any left or right edge that isn't aligned to a
 multiple-of-four pixel column (that is, a column at which one four-pixel
 set ends and the next begins) must be clipped via the Map Mask register,