cgroups: improve indentation

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>

Cgroups/linux-cgroups-1.md

@@ -195,7 +195,9 @@ So, during startup of a `docker` container, `docker` will create a `cgroup` for
 ```
 $ docker exec -it mysql-work /bin/bash
 $ top
- PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                   1 mysql     20   0  963996 101268  15744 S   0.0  0.6   0:00.46 mysqld                                                                                  71 root      20   0   20248   3028   2732 S   0.0  0.0   0:00.01 bash                                                                                    77 root      20   0   21948   2424   2056 R   0.0  0.0   0:00.00 top                                                                                  
+  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                   1 mysql     20   0  963996 101268  15744 S   0.0  0.6   0:00.46 mysqld
+   71 root      20   0   20248   3028   2732 S   0.0  0.0   0:00.01 bash
+   77 root      20   0   21948   2424   2056 R   0.0  0.0   0:00.00 top
 ```
 
 And we may see this `cgroup` on host machine: