update the actual minor core-js version in the README

README.md

@@ -213,9 +213,9 @@ import 'regenerator-runtime/runtime';
 
 #### `@babel/preset-env`[⬆](#index)
 
-[`@babel/preset-env`](https://github.com/babel/babel/tree/master/packages/babel-preset-env) has `useBuiltIns` option, which optimizes working with global version of `core-js`. With `useBuiltIns` option, you should also set `corejs` option to used version of `core-js`, like `corejs: '3.6'`.
+[`@babel/preset-env`](https://github.com/babel/babel/tree/master/packages/babel-preset-env) has `useBuiltIns` option, which optimizes working with global version of `core-js`. With `useBuiltIns` option, you should also set `corejs` option to used version of `core-js`, like `corejs: '3.7'`.
 
-> **Warning!** Recommended to specify used minor `core-js` version, like `corejs: '3.6'`, instead of `corejs: 3`, since with `corejs: 3` will not be injected modules which were added in minor `core-js` releases.
+> **Warning!** Recommended to specify used minor `core-js` version, like `corejs: '3.7'`, instead of `corejs: 3`, since with `corejs: 3` will not be injected modules which were added in minor `core-js` releases.
 
 - `useBuiltIns: 'entry'` replaces imports of `core-js` to import only required for a target environment modules. So, for example,
 ```js
@@ -270,7 +270,7 @@ import 'core-js/modules/es.array.of';
 var array = Array.of(1, 2, 3);
 ```
 
-By default, `@babel/preset-env` with `useBuiltIns: 'usage'` option only polyfills stable features, but you can enable polyfilling of proposals by `proposals` option, as `corejs: { version: '3.6', proposals: true }`.
+By default, `@babel/preset-env` with `useBuiltIns: 'usage'` option only polyfills stable features, but you can enable polyfilling of proposals by `proposals` option, as `corejs: { version: '3.7', proposals: true }`.
 
 #### `@babel/runtime`[⬆](#index)