Update README

README.md

@@ -1,8 +1,43 @@
 # GSoC 2017 - Jingle File Transfer Demo App
-File synchronisation via XMPP.
+##File synchronisation via XMPP.
 
 xmpp_sync has two modes: Master and Slave mode. A client started in master mode will send files 
 out, while clients in slave mode will receive files.
 
 In order to use the program, you need at least two XMPP accounts (which might be on different 
 servers). I recommend using a server, which supports Socks5 proxies.
+
+###Available options and commands:
+
+The application has the following options available when being started.
+```
+usage: client [-d] -D <arg> [-h] [-m] -p <swordfish> -u <user@server.tld>
+ -d,--debug                        Print debug messages to the console.
+ -D,--directory <arg>              Directory which will be synced.
+ -h,--help                         Display this help text.
+ -m,--master                       Start in master mode. When this flag is
+                                   missing, the client will be started in
+                                   slave mode.
+ -p,--password <swordfish>         Password of the XMPP account.
+ -u,--username <user@server.tld>   Barejid of the XMPP account.
+```
+
+So in order to start the application in master mode, you can use the following command:
+
+`java -jar xmpp_sync.jar -u user@server.tld -p password123 -m -D master/directory`
+
+If you want to start the application in slave mode instead, just leave out the `-m` flag.
+
+There is a number of commands available to control the application once it is started.
+
+```
+ /help                             Display a help text
+ /add <contact@otherserver.tld>    Add a contact to the contact list (roster).
+ /trust <contact@otherserver.tld>  Trust a contacts OMEMO fingerprints.
+ /sync <contact@otherserver.tld>   Add a contacts device to the sync list.
+ /quit                             Stop the application.
+```
+
+Once you added a contact to your roster, you can add its devices to the sync list. Whenever you now drop a file into the master folder, it will be sent out OMEMO encrypted to all slave devices on the 
+sync list. The OMEMO encryption is done using Smack's OMEMO capabilities, I implemented prior to GSoC and my [JET](https://geekplace.eu/xeps/xep-jet/xep-jet.html) specification which was part of my 
+project.