Add boilerplate code

gym_dora/example.py

@@ -0,0 +1,17 @@
+import gymnasium as gym
+
+import gym_dora  # noqa: F401
+
+env = gym.make("gym_dora/DoraAloha-v0", disable_env_checker=True)
+obs = env.reset()
+
+policy = ...  # make_policy
+
+done = False
+while not done:
+    actions = policy.select_action(obs)
+    observation, reward, terminated, truncated, info = env.step(actions)
+
+    done = terminated | truncated | done
+
+env.close()