[Serving] Add a simple Python serving (#962)

* init simple serving

* simple serving is working

* ppyoloe demo

* Update README_CN.md

* update readme

* complete vision result to json

examples/vision/detection/paddledetection/python/serving/server.py

@@ -0,0 +1,40 @@
+import fastdeploy as fd
+import os
+import logging
+
+logging.getLogger().setLevel(logging.INFO)
+
+# Get arguments from envrionment variables
+model_dir = os.environ.get('MODEL_DIR')
+device = os.environ.get('DEVICE', 'cpu')
+use_trt = os.environ.get('USE_TRT', False)
+
+# Prepare model, download from hub or use local dir
+if model_dir is None:
+    model_dir = fd.download_model(name='ppyoloe_crn_l_300e_coco')
+
+model_file = os.path.join(model_dir, "model.pdmodel")
+params_file = os.path.join(model_dir, "model.pdiparams")
+config_file = os.path.join(model_dir, "infer_cfg.yml")
+
+# Setup runtime option to select hardware, backend, etc.
+option = fd.RuntimeOption()
+if device.lower() == 'gpu':
+    option.use_gpu()
+if use_trt:
+    option.use_trt_backend()
+    option.set_trt_cache_file('ppyoloe.trt')
+
+# Create model instance
+model_instance = fd.vision.detection.PPYOLOE(
+    model_file=model_file,
+    params_file=params_file,
+    config_file=config_file,
+    runtime_option=option)
+
+# Create server, setup REST API
+app = fd.serving.SimpleServer()
+app.register(
+    task_name="fd/ppyoloe",
+    model_handler=fd.serving.handler.VisionModelHandler,
+    predictor=model_instance)