docs: update docs

Author: kagawagao

docs/guide/index.md

@@ -4,12 +4,12 @@ title: Guide
 
 ## What
 
-`G2Plot Vue` is a chart component set powered by [`G2Plot`](https://g2plot.antv.vision/) and developed for `Vue 3`.
+`G2Plot Vue` is a chart component set powered by [`G2Plot`](https://g2plot.antv.vision/).
 
 ## Features
 
 - Fully support `G2Plot` charts, and will support new chart at first time.
-- Developed for `Vue 3`, and easily use.
+- Both `Vue 2&3` support, and easily use.
 - Native support for `TypeScript`.
 - **100%** unit test coverage
 

docs/index.md

@@ -5,11 +5,23 @@ heroImage: /logo.png
 actionText: Get Started
 actionLink: /guide/
 features:
-  - title: Vue
+  - title: Both Vue 2&3
     details: Universal support with vue-demi
   - title: G2Plot
     details: Powered by G2Plot
   - title: TypeScript
     details: Fully type definitions support
 footer: MIT Licensed | Copyright © 2020-present Open Data Plan
 ---
+
+## Install
+
+```
+npm install @opd/g2plot-vue
+```
+
+`g2plot-vue` will auto switch export version based on your installed `vue` version, if not work, you can switch by follow:
+
+```bash
+node ./node_modules/@opd/g2plot-vue/scripts/postinstall.js
+```