Update 'README.md'

README.md

@@ -3,7 +3,7 @@
 to install:
 - Windows: [WinSCP](https://winscp.net/eng/index.php) or [Cyberduck](https://cyberduck.io/)
 - MacOS: [Cyberduck](https://cyberduck.io/)
-- Linux: scp command tool (should be installed on default)
+- Linux: scp command line tool (should be installed on default)
 
 resources used during tutorial:
 - address to centurio user interface: http://\<ip_address\>/ui