doc: cgroup: improve formatting of cpuset examples

We need literal sections otherwise the entire example is rendered
as a single line.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20200228000653.1572553-5-kuba@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/cgroup-v2.rst

@@ -1841,7 +1841,7 @@ Cpuset Interface Files
 	from the requested CPUs.
 
 	The CPU numbers are comma-separated numbers or ranges.
-	For example:
+	For example::
 
 	  # cat cpuset.cpus
 	  0-4,6,8-10
@@ -1880,7 +1880,7 @@ Cpuset Interface Files
 	from the requested memory nodes.
 
 	The memory node numbers are comma-separated numbers or ranges.
-	For example:
+	For example::
 
 	  # cat cpuset.mems
 	  0-1,3