Readme example uses the wrong command line options #21

The command line example in the readme uses the wrong options:

https://github.com/Jumoo/uSync.CommandLine/blob/de15939/readme.md?plain=1#L94

uSyncCli usync-ping -s https://localhost:44359 -s [client_secret] -k [client_id]

-s appears twice, and -k is given the client id. The options are defined here:

https://github.com/Jumoo/uSync.CommandLine/blob/de15939/uSync.Commands.Core/Commands/SyncCommandBase.cs#L20-L22

• -s / --server-url: server URL
• -k / --secret: client secret
• -i / --client-id: client id

The example should read:

uSyncCli usync-ping -s https://localhost:44359 -k [client_secret] -i [client_id]