Update README.md

Typos correction and small reorganization

README.md

@@ -4,13 +4,14 @@ Simple tool to handle LabCalcolo's VMs.
 usage: labcalcolo [{status,start,stop,doctor}] [options]
 
 positional arguments:
-  {status,start,stop, doctor}  Specify command to execute, default is 'status'
-
-    status             check whether there are VMs running on the considered nodes
+    status             default. Check whether there are VMs running on the considered nodes
+    
     start, stop        start and stop VMs
-    doctor             check if qemu and spicec are running. If qemu is running, but spicec is not, ask if the want to start it
+    
+    doctor             check if qemu and spicec are running. If qemu is running, but spicec is not, ask user if (s)he wants to start it
 
 optional arguments:
+
   -h, --help           show this help message and exit
   
   -a, --all            All LCM nodes are considered