[core][doc] modification in the develop guide

doc/develop.rst

@@ -20,6 +20,7 @@
 .. You should have received a copy of the GNU Affero Public License along     ..
 .. with the BEAT platform. If not, see http://www.gnu.org/licenses/.          ..
 
+.. _beat-core-local-development:
 
 ===================
  Local Development
@@ -79,6 +80,12 @@ downloaded from the BEAT platform (not required for unit testing). These docker
   $ docker pull docker.idiap.ch/beat/beat.env.python:1.0.0
   $ docker pull docker.idiap.ch/beat/beat.env.db:1.2.2
 
+To run an experiment using docker you should specify the docker image when defining the experiment, then use the `--docker` flag when using `beat.cmdline`::
+
+  $ beat experiment run --docker <experiment name>
+
+You can find more information about running experiments locally using different executors in :ref:`here <beat-cmdline-experiments-running>`.
+
 
 Documentation
 -------------