Change heading level of 'Original code'

In the case where we recommend trying the alternate code first, the
lower section is 'Original code' but this was at heading level 3 when
discussion suggests 2 so this was done as well:

    sgit -e 's/^### \(Original code\)/## \1/g' '*README.md'

1996/eldby/README.md

@@ -35,7 +35,7 @@ make CFLAGS+="-DZ=20000" clobber alt
 ./eldby.alt
 ```
 
-### Original code:
+## Original code:
 
 Besides the fact that modern systems make it impossible to see what this program
 does the rapid movement can be a problem for some people. It is for these