Add demo file

send_obs.py

+from mlagents_envs.environment import UnityEnvironment
+from mlagents_envs.side_channel.agent_parameters_channel import AgentParametersChannel
+
+
+# Getting observation types
+agent_params = AgentParametersChannel()
+env = UnityEnvironment(side_channels=[agent_params])
+env.reset()
+bspec = list(env.behavior_specs.values())[0]
+print(bspec.sensor_types)
+dsteps, tsteps = env.get_steps(list(env.behavior_specs.keys())[0])
+print(dsteps.obs)
+
+# Sending agent parameterizations
+for i, _id in enumerate(dsteps.agent_id):
+    agent_params.set_float_parameter(_id, "test_param", i * 1000)
+env.reset()
+env.step()