docs: rewrite docs use docusaurus (#853)

docs/README.md

@@ -0,0 +1,25 @@
+# DB-GPT Website
+
+## Quick Start
+
+### Install dependencies 
+- Clone current project firstly!
+- Install docusaurus dependencies, generate node_modules folder.
+
+```
+sudo yarn install
+```
+
+### launch
+``` 
+yarn start
+```
+
+The default service starts on port `3000`, visit `localhost:3000`
+
+## Docker development 
+
+```commandline
+docker build -t dbgptweb .
+docker run --restart=unless-stopped -d -p 3000:3000 dbgptweb
+```