Add documentation to readme file

Signed-off-by: Dries Vints <dries.vints@gmail.com>
New way for adding users in a config file

User nicknames are now the array keys. This helps for making sure we use unique user names.

Signed-off-by: Dries Vints <dries.vints@gmail.com>
Add default user configuration option

A default user can now be set in the config file. This allows for environment specific default users and automatic user identification.

Signed-off-by: Dries Vints <dries.vints@gmail.com>