Mention new location

Ref. babel/babel#6499.

README.md

@@ -1,59 +1,3 @@
 # babel-plugin-transform-unicode-property-regex [![Build status](https://travis-ci.org/mathiasbynens/babel-plugin-transform-unicode-property-regex.svg?branch=master)](https://travis-ci.org/mathiasbynens/babel-plugin-transform-unicode-property-regex)
 
-Compile [Unicode property escapes](https://github.com/mathiasbynens/regexpu-core/blob/master/property-escapes.md) (`\p{…}` and `\P{…}`) in Unicode regular expressions to ES5 or ES6 that works in today’s environments.
-
-**Note:** the Unicode property escape syntax is non-standard and may or may not reflect what eventually gets specified.
-
-[Here’s an online demo.](https://mothereff.in/regexpu#input=var+regex+%3D+/%5Cp%7BScript_Extensions%3DGreek%7D/u%3B&unicodePropertyEscape=1)
-
-## Installation
-
-```sh
-$ npm install babel-plugin-transform-unicode-property-regex
-```
-
-## Usage
-
-### Via `.babelrc` (recommended)
-
-`.babelrc`
-
-```json
-{
-  "plugins": ["transform-unicode-property-regex"]
-}
-```
-
-### Via CLI
-
-```sh
-$ babel --plugins transform-unicode-property-regex script.js
-```
-
-### Via Node.js API
-
-```js
-require('babel-core').transform(code, {
-  'plugins': ['transform-unicode-property-regex']
-});
-```
-
-To transpile to ES6/ES2015:
-
-```js
-require('babel-core').transform(code, {
-  'plugins': [
-    ['transform-unicode-property-regex', { 'useUnicodeFlag': true }]
-  ]
-});
-```
-
-## Author
-
-| [![twitter/mathias](https://gravatar.com/avatar/24e08a9ea84deb17ae121074d0f17125?s=70)](https://twitter.com/mathias "Follow @mathias on Twitter") |
-|---|
-| [Mathias Bynens](https://mathiasbynens.be/) |
-
-## License
-
-This code is available under the [MIT](https://mths.be/mit) license.
+This plugin was [moved into the main Babel repository](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-unicode-property-regex/README.md).