Improve README.md

Author: vaniyokk

README.md

@@ -1,2 +1,37 @@
 # vuepress-plugin-alias
 Vuepress plugin that generates alias pages for proper redirect handling
+
+## Install
+
+* Yarn
+
+  ```sh
+  yarn add vuepress-plugin-alias
+  ```
+
+## Usage
+
+### Vuepress v1.x
+
+```js
+// .vuepress/config.js
+module.exports = {
+  plugins: [ 'alias' ]
+}
+```
+
+and in your front-matter add alias to redirect from
+
+```md
+---
+alias: old-link.html
+---
+```
+or a list of aliases
+```md
+---
+aliases: 
+ - old-link1.html
+ - old-link2.html
+---
+```