Avoid mentioning the solution in problem section for Virtual Machine

According to the style guide, the section of "Problem it addresses"
should focus on the problem, not the solution. Therefore, I think it
makes sense not to mention virtual machine and virtualization in
that section.

Signed-off-by: John Lin <[email protected]>

Author: johnlinp

content/en/virtual-machine.md

@@ -15,7 +15,6 @@ easily create and destroy VMs without impacting the underlying hardware.
 
 ## Problem it addresses
 
-Virtual machines take advantage of virtualization. 
 When a [bare metal](/bare-metal-machine/) machine is bound to a single operating system, 
 how well the machine's resources can be used is somewhat limited. 
 Also, when an operating system is bound to a single physical machine,