Update hddtemp.rst

docs/aoa/hddtemp.rst

@@ -15,13 +15,17 @@ On your Linux system, you will need to have:
 For example on a CentOS/Redhat Linux operating system, you have to:
 
     $ sudo yum install hddtemp
+    
     $ sudo systemctl enable hddtemp
+    
     $ sudo systemctl enable hddtemp
 
 Test it in the console:
 
     $ hddtemp
+    
     /dev/sda: TOSHIBA MQ01ACF050: 41°C
+    
     /dev/sdb: ST1000LM044 HN-M101SAD: 38°C
 
 It should appears in the sensors plugin.