Updated README.

README.md

 [![pipeline status](https://git.dynare.org/Dynare/dseries/badges/master/pipeline.svg)](https://git.dynare.org/Dynare/dseries/commits/master)
 
-This MATLAB/Octave toolbox comes with two classes:
+This MATLAB/Octave toolbox comes with three classes:
 
  - `@dates` which is used to handle dates.
  - `@dseries` which is used to handle time series data.
+ - `@x13` which provides an interface to X13-ARIMEA-SEATS.
 
 The package is a dependence of
 [Dynare](https=//git.dynare.org/Dynare/dynare), but can also be used
@@ -27,13 +28,12 @@ or downloading a zip archive:
 
 Add the `dseries/src` folder to the MATLAB/Octave path, and run the following command (on MATLAB/Octave) prompt:
 
-    >> dseries().initialize()
+    >> initialize_dseries_class
 
 which, depending on your system, will add the necessary subfolders to
 the MATLAB/Octave path.
 
-You are then ready to go. A full documentation will come soon,
-but you can already obtain a general idea by looking into the Dynare
+You are then ready to go. A full documentation is available in the Dynare
 reference manual.
 
 Note that [X13-ARIMA-SEATS](https://www.census.gov/srd/www/x13as/) is required