Add simplified download command (#1234)

* Simplify the download command(microsoft#1232)

* Update simplified download instruction

README.md

@@ -176,6 +176,19 @@ Also, users can install the latest dev version ``Qlib`` by the source code accor
 
 ## Data Preparation
 Load and prepare data by running the following code:
+
+### Get with module
+  ```bash
+  # get 1d data
+  python -m qlib.run.get_data qlib_data --target_dir ~/.qlib/qlib_data/cn_data --region cn
+
+  # get 1min data
+  python -m qlib.run.get_data qlib_data --target_dir ~/.qlib/qlib_data/cn_data_1min --region cn --interval 1min
+
+  ```
+
+### Get from source
+
   ```bash
   # get 1d data
   python scripts/get_data.py qlib_data --target_dir ~/.qlib/qlib_data/cn_data --region cn

qlib/run/get_data.py

@@ -0,0 +1,9 @@
+#  Copyright (c) Microsoft Corporation.
+#  Licensed under the MIT License.
+
+import fire
+from qlib.tests.data import GetData
+
+
+if __name__ == "__main__":
+    fire.Fire(GetData)