Add labels for manual training snippets

docs/source/snippets/trainer.py

@@ -237,3 +237,43 @@ def eval(self) -> None:
 for timestep in range(cfg["timesteps"]):
     trainer.eval(timestep=timestep)
 # [jax-end-step]
+
+# =============================================================================
+
+# [pytorch-start-manual-training]
+
+# [pytorch-end-manual-training]
+
+# [pytorch-start-manual-evaluation]
+# assuming there is an environment named 'env'
+# and an agent named 'agents' (or a state-preprocessor and a policy)
+
+states, infos = env.reset()
+
+for i in range(1000):
+    # state-preprocessor + policy
+    with torch.no_grad():
+        states = state_preprocessor(states)
+        actions = policy.act({"states": states})[0]
+
+    # step the environment
+    next_states, rewards, terminated, truncated, infos = env.step(actions)
+
+    # render the environment
+    env.render()
+
+    # check for termination/truncation
+    if terminated.any() or truncated.any():
+        states, infos = env.reset()
+    else:
+        states = next_states
+# [pytorch-end-manual-evaluation]
+
+
+# [jax-start-manual-training]
+
+# [jax-end-manual-training]
+
+# [jax-start-manual-evaluation]
+
+# [jax-end-manual-evaluation]