add doc to insert new generic action with ros service

docs/source/index.rst

@@ -32,6 +32,7 @@ Documentation about the API of ROS End-Effector can be found at https://advrhuma
    actions
    findActions
    receiveActionsInfo
+   newGenericAction
    rosTopics  
 
 .. toctree::

docs/source/newGenericAction.rst

@@ -0,0 +1,78 @@
+.. _newGenericAction:
+
+.. role:: raw-html(raw)
+  :format: html
+
+How to add a new Generic action in the system
+===================================================
+
+When ROSEE main node is running, you may want to introduce a new action in the system, such that you can command it afterwards. This is possible through a dedicated ROS service.
+
+.. note::
+  The action will belong to the *generic* category
+
+The request is composed as following:
+
+.. code-block:: sh
+
+	## Service associated with GenericGraspingAction message
+
+	NewGenericGraspingAction newAction
+
+	# user can also request to store the action in a yaml file, togheter with the others
+	bool emitYaml
+
+	---
+
+	# the service will give true if action is good and it is inserted in the structure
+	bool accepted
+
+	# true false depending if emission on yaml file is successful
+	bool emitted
+
+	# string containing useful info about a possible not acceptance
+	string error_msg
+
+Where NewGenericGraspingAction is defined as: 
+
+.. code-block:: sh
+
+	# Message which include all the infos necessary to insert a new action in the system 
+	# (https://github.com/ADVRHumanoids/ROSEndEffector/issues/71)
+
+	# name of the action
+	string action_name
+
+	# Motor Position
+	MotorPosition action_motor_position
+
+	# OPTIONAL The mask which says if the motor is used by the action (count > 0) or not (count = 0).
+	# take care that if it is not included, the not used joint will be considered the ones with 0 position
+	JointsInvolvedCount action_motor_count
+		                                
+	# OPTIONAL field to indicate which hand element will be moved by the action
+	string[] elements_involved
+
+
+Hence you can call the service from usual c++ code or also from terminal for example:
+
+.. code-block:: bash
+
+	rosservice call /ros_end_effector/new_generic_grasping_action "newAction:
+		action_name: 'newFancyAction'
+		action_motor_position:
+		  name:
+		  - 'joint_1'
+		  - 'joint_2'
+		  position:
+		  - 1
+		  - 2
+	emitYaml: true" 
+
+.. warning::
+
+  Some checks are performed when calling the action (eg no action with the same name must exists, consistency among motor position and motor count...) 
+  but NO CHECKS are performed to see if the name of the joints are the correct ones. Remember to put ALL the motors in the action_motor_position field!
+
+
+