expand to 'used b2d vm on any of the platforms'

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)

docs/sources/userguide/usingdocker.md

@@ -179,8 +179,9 @@ see the application.
 Our Python application is live!
 
 > **Note:**
-> If you have used boot2docker on OSX, or Windows, you'll need to get the IP of the virtual
-> host instead of using localhost. You can do this by running the following in
+> If you have used the boot2docker virtual machine on OSX, Windows or Linux,
+> you'll need to get the IP of the virtual host instead of using localhost.
+> You can do this by running the following in
 > the boot2docker shell.
 > 
 >     $ boot2docker ip