doc: Update README for the migration info

Author: yeslee-houzz

README.md

@@ -1,7 +1,44 @@
 # eslint-config-ivy
 
+> ⚠️ **CAUTION**  
+> We now have a published package available! However, since package name has changed from `eslint-config-ivy` to `@houzz/eslint-config-ivy`, we need to maintain two branches for backward compatibility for now.
+
+-   master: For legacy usage (`github:Houzz/eslint-config-ivy#master`).
+-   [release](https://github.com/Houzz/eslint-config-ivy/tree/release): For the new package (`@houzz/eslint-config-ivy`).
+
+Please migrate all old usages to the new package as soon as possible. The legacy branch will eventually be deprecated.
+
 ## Usage
 
+New (Recommended): Install the latest version from npm
+
+```sh
+npm install @houzz/eslint-config-ivy --save-dev
+```
+
+```json
+// .eslintrc
+{
+    "extends": ["@houzz/eslint-config-ivy"]
+}
+```
+
+Legacy (Deprecated): For temporary backward compatibility
+
 ```sh
 npm install github:Houzz/eslint-config-ivy#master
 ```
+
+```json
+// .eslintrc
+{
+    "extends": ["eslint-config-ivy"]
+}
+```
+
+## Publish
+
+Push to the `release` branch to publish the package.
+
+-   [Action](https://github.com/Houzz/eslint-config-ivy/actions/workflows/npmpublish.yml)
+-   [Package](https://github.com/orgs/Houzz/packages/npm/package/eslint-config-ivy)