Update nextcloudcmd.rst

Debian has a package in its repository for nextcloudcmd. Adding an Ubuntu ppa to Debian might work, but is not the preferable solution.

Signed-off-by: mayonezo <haselnuss87@gmail.com>

doc/nextcloudcmd.rst

@@ -19,7 +19,7 @@ CentOS
     $ sudo yum -y install epel-release
     $ sudo yum -y install nextcloud-client
 
-Ubuntu/Debian
+Ubuntu
 
 ::
 
@@ -27,6 +27,12 @@ Ubuntu/Debian
     $ sudo apt update
     $ sudo apt install nextcloud-client
 
+Debian
+
+::
+
+    $ sudo apt install nextcloud-desktop-cmd
+
 
 Refer to the link