Document in High-level (#93)

* Add init information

* Adjust order and move content

* GPU support

* edit docs

* README structure

* Update Dockerfile

* Update rdagent/utils/env.py

* Update read the docs

* Update framework

docs/project_framework_introduction.rst

@@ -1,18 +1,27 @@
 ===============================
-Project framework introduction
+Framework Design & Components
 ===============================
 
-title1
+Framework & Components
 =========================
 
-content1
+- TODO: Components & Feature Level
 
-title2
+- Class Level Figure
+
+Detailed Design
 =========================
 
-content2
 
-title3
-=========================
+Configuration
+-------------
+
+You can manually source the `.env` file in your shell before running the Python script:
+Most of the workflow are controlled by the environment variables.
+```sh
+# Export each variable in the .env file; Please note that it is different from `source .env` without export
+export $(grep -v '^#' .env | xargs)
+# Run the Python script
+python your_script.py
+```
 
-content3