Add gpt2-medium-en.

Author: Xreki

paddle_samples/PaddleNLP/gpt2-medium-en/graph_net.json

@@ -0,0 +1,6 @@
+{
+    "framework": "paddle",
+    "model_name": "gpt2-medium-en",
+    "num_devices_required": 1,
+    "num_nodes_required": 1
+}

paddle_samples/PaddleNLP/gpt2-medium-en/input_meta.py

@@ -0,0 +1,25 @@
+class Program_weight_tensor_data_0:
+    name = "data_0"
+    shape = [1, 19]
+    dtype = "int64"
+    data = [
+        15496,
+        11,
+        616,
+        1438,
+        318,
+        5811,
+        13,
+        314,
+        716,
+        4673,
+        546,
+        1588,
+        3303,
+        4981,
+        290,
+        511,
+        45619,
+        13,
+        220,
+    ]