Add documentation

Author: cesarBLG

Source/Documentation/Manual/images/options-raildriver.png

@@ -502,6 +502,33 @@ By clicking on *Export* a printable text file ``Open Rails
 Keyboard.txt`` is generated on the desktop, showing all links between
 commands and keys.
 
+RailDriver Options
+==================
+
+.. image:: images/options-raildriver.png
+
+This tab allows configuring a RailDriver device. In this panel you will
+find listed the RailDriver buttons that are associated
+with all ORTS commands.
+
+You can modify them by clicking on a field and pressing the new desired
+button. Three symbols will appear at the right of the field: with the first
+one you validate the change, with the second one you cancel it, with the
+third one you return to the default value.
+
+By clicking on *Check* ORTS verifies that the changes made are compatible,
+that is, that there is no button that is used for more than one command.
+
+By clicking on *Defaults* all changes that were made are reset, and the
+default values are reloaded.
+
+By clicking on *Export* a printable text file ``Open Rails
+RailDriver.txt`` is generated on the desktop, showing all links between
+commands and buttons.
+
+By clicking on *Calibrate* a guided procedure will be started to
+calibrate all RailDriver levers.
+
 Data Logger Options
 ===================