[Examples] Add example on how to load a Romeo with Python

examples/python/README.md

+# Pinocchio examples in Python
+
+This directory contains minimal examples on how to use **Pinocchio** with the Python bindings. 

examples/python/load-romeo.py

+import pinocchio as pin
+from pinocchio.romeo_wrapper import RomeoWrapper
+
+## Load Romeo with RomeoWrapper
+import os
+current_path = os.getcwd()
+
+# The model of Romeo is contained in the path PINOCCHIO_GIT_REPOSITORY/models/romeo
+model_path = current_path + "/" + "../../models/romeo"
+mesh_dir = model_path
+urdf_filename = "romeo.urdf"
+urdf_model_path = model_path + "/urdf/" + urdf_filename
+
+robot = RomeoWrapper(urdf_model_path, [mesh_dir])
+
+## alias
+model = robot.model
+data = robot.data
+
+## do whatever, e.g. compute the center of mass position in the world frame
+q0 = robot.q0
+com = robot.com(q0)
+# This last command is similar to
+com2 = pin.centerOfMass(model,data,q0)