update function description for eyetarcker

Author: marcobarilari

src/eyeTracker.m

@@ -1,29 +1,37 @@
 % (C) Copyright 2020 CPP_PTB developers
 
 function [el, cfg] = eyeTracker(input, cfg, varargin)
-    % [el] = eyeTracker(input, cfg, varargin)
     %
     % Wrapper function that deals with all the necessery actions to implement
-    %  Eye Tracker recording with eyelink.
+    % Eye Tracker recording with eyelink.
     %
-    % INPUT
+    % USAGE:
     %
-    % - action: Defines what we want the function to do
-    %  - Calibration: to initialize EyeLink and run calibration
-    %    -- 'default calibration' (default) will run a calibration with 6 points
-    %    -- 'custom calibration'  (cfg.eyeTracker.defaultCalibration = 'false') will run a
-    %        calibration with 6 points but the experimenter can choose their position on the screen
-    %  - StartRecording: to start eye movements recording
-    %  - Message: will add a tag (e.g. 'Block_n1') in the ET output file, the tag is a string and it
-    %        is input from `varargin`
-    %  - StopRecordings: to stop eye movements recornding
-    %  - Shutdown: to save the `.edf` file with BIDS compliant name, from cpp-lln-lab/CPP_BIDS, in
-    %    the output folder and shut the connection between the stimulation computer and the EyeLink
-    %    computer
+    %   function [el, cfg] = eyeTracker(input, cfg, [message])
     %
-    %  OUTPUT
+    % :param input: action: Defines what we want the function to do:
+    %               - Calibration: to initialize EyeLink and run calibration
+    %                 - 'default calibration' (default) will run a calibration with 6 points
+    %                 - 'custom calibration'  (cfg.eyeTracker.defaultCalibration = 'false') will run
+    %                   a calibration with 6 points but the experimenter can choose their position
+    %                   on the screen
     %
-    % `el` is a structure where are stored EyeLink setup variables
+    %               - StartRecording: to start eye movements recording
+    %               - Message: will add a tag (e.g. 'Block_n1') in the ET output file, the tag is a
+    %                 string and it is input from `varargin`
+    %               - StopRecordings: to stop eye movements recornding
+    %               - Shutdown: to save the `.edf` file with BIDS compliant name, from
+    %                 cpp-lln-lab/CPP_BIDS, in the output folder and shut the connection between the
+    %                 stimulation computer and the EyeLink computer
+    % :type input: string
+    % :param cfg: structure that stores any info regarding the experiment
+    % :type cfg: struct
+    % :param message: optional argument to pass in when you want to tag the output in a specific
+    %                 moment of the experiment (for example ``Experiment-start``)
+    % :type message: string
+    %
+    % :returns: - :el: (struct) stores info related to the Eye Tracker
+    %           - :cfg: (struct)
 
     if ~cfg.eyeTracker.do