docs: Add info about vOn to README

Author: nickmessing

packages/babel-preset-jsx/README.md

@@ -45,3 +45,4 @@ Options are:
 - `functional` [@vue/babel-sugar-functional-vue](../babel-sugar-functional-vue/README.md) - Functional components syntactic sugar
 - `injectH` [@vue/babel-sugar-inject-h](../babel-sugar-inject-h/README.md) - Automatic `h` injection syntactic sugar
 - `vModel` [@vue/babel-sugar-v-model](../babel-sugar-v-model/README.md) - `vModel` syntactic sugar
+- `vOn` [@vue/babel-sugar-v-on](../babel-sugar-v-on/README.md) - `vOn` syntactic sugar

packages/babel-sugar-v-on/README.md

@@ -0,0 +1,52 @@
+## @vue/babel-sugar-v-on
+
+Syntactic sugar for v-on in JSX.
+
+### Babel Compatibility Notes
+
+- This repo is only compatible with Babel 7.x, for 6.x please use [vuejs/babel-plugin-transform-vue-jsx](https://github.com/vuejs/babel-plugin-transform-vue-jsx)
+
+### Usage
+
+Install the dependencies:
+
+```sh
+# for yarn:
+yarn add @vue/babel-sugar-v-on
+# for npm:
+npm install @vue/babel-sugar-v-on --save
+```
+
+In your `.babelrc`:
+
+```json
+{
+  "plugins": ["@vue/babel-sugar-v-on"]
+}
+```
+
+However it is recommended to use the [configurable preset](../babel-preset-jsx/README.md) instead.
+
+### Details
+
+This plugin adds v-on to the JSX and tries to mirror the same behaviour as in vue-template-compiler, with a few differences:
+
+1.  You should use underscore (`_`) instead of dot (`.`) for modifiers (`vOn:click_prevent={this.test}`)
+2.  It is recommended to use camelCase version of it (`vOn`) in JSX, but you can use kebab-case too (`v-on`).
+
+```js
+export default {
+  methods: {
+    test() {
+      console.log('Hello World')
+    },
+  },
+  render(h) {
+    return (
+      <div>
+        <a href="https://vuejs.org" vOn:click={this.test}>Vue</a>
+      </div>
+    )
+  },
+}
+```