docs: update .env.example

Author: ChenZiHong-Gavin

.env.example

@@ -35,3 +35,23 @@ TRAINEE_API_KEY=
 #
 # TRAINEE_BACKEND=huggingface
 # TRAINEE_MODEL=Qwen/Qwen2.5-0.5B-Instruct
+
+# # sglang
+# SYNTHESIZER_BACKEND=sglang
+# SYNTHESIZER_MODEL=Qwen/Qwen2.5-0.5B-Instruct
+# SYNTHESIZER_TP_SIZE=1
+# SYNTHESIZER_NUM_GPUS=1
+
+# TRAINEE_BACKEND=sglang
+# TRAINEE_MODEL=Qwen/Qwen2.5-0.5B-Instruct
+# SYNTHESIZER_TP_SIZE=1
+# SYNTHESIZER_NUM_GPUS=1
+
+# # vllm
+# SYNTHESIZER_BACKEND=vllm
+# SYNTHESIZER_MODEL=Qwen/Qwen2.5-0.5B-Instruct
+# SYNTHESIZER_NUM_GPUS=1
+
+# TRAINEE_BACKEND=vllm
+# TRAINEE_MODEL=Qwen/Qwen2.5-0.5B-Instruct
+# TRAINEE_NUM_GPUS=1