When indentation is used to create a code block immediately following a list, Markdown syntax is ambiguous: it can be interpreted as another text paragraph belonging to the last list entry, or as a standalone code block. The original behavior in CL 197637 made this unambiguously a code block because the present format did not support lists. This changed when the article was converted to use Markdown syntax in CL 222848. Start using a fenced code block instead of indentation to resolve the Markdown ambiguity and restore original behavior. For golang/go#33955. Change-Id: I9537bc72d7a32f90592942591b2688fb2f26c452 Reviewed-on: https://go-review.googlesource.com/c/blog/+/245017 Reviewed-by: Jean de Klerk <deklerk@google.com>