[feat] Add texteller training script

examples/client_demo.py

@@ -0,0 +1,10 @@
+import requests
+
+server_url = "http://127.0.0.1:8000/predict"
+
+img_path = "/path/to/your/image"
+with open(img_path, 'rb') as img:
+    files = {'img': img}
+    response = requests.post(server_url, files=files)
+
+print(response.text)