Update README.md

Updated documentation

README.md

@@ -7,6 +7,30 @@ A PHP library for sending WOL (Wake-On-LAN) notifications across a network. In o
 ## Example usage
 
 ```PHP
-WOL::wake('192.168.1.2', '6A:70:D0:F0:B0:50');
+Wol::wake('192.168.1.2', '6A:70:D0:F0:B0:50');
 ```
 The result of this will return the number of bytes sent to the target if successful, otherwise it will return `FALSE`.
+
+
+## Errors
+
+### Broadcast IP address and MAC address required.
+In order to use WOL it is necessary to provide a broadcast IP address and the MAC address of the machine to wake (or turn on).
+
+
+### Invalid protocol
+Only supported protocols may be used; these are:
+
+| Protocol | Description |
+| :------: | :---------- |
+| AF_INET | IPv4 Internet based protocols. TCP and UDP are common protocols of this protocol family. |
+| AF_INET6 | IPv6 Internet based protocols. TCP and UDP are common protocols of this protocol family. |
+| AF_UNIX | Local communication protocol family. High efficiency and low overhead make it a great form of IPC (Interprocess Communication). |
+
+
+### Connection failed
+This indicates that the socket could not be created. This could be down to permissions, socket extension not being loaded, etc.
+
+
+### Unable to set options on socket
+Although the socket could be created, this indicates that the settings that are attempting to be applied to the socket are not supported.