doc: update README.md

Author: jaywcjlove

core/README.md

@@ -60,6 +60,7 @@ npm install @uiw/react-codemirror --save
 | `@uiw/codemirror-theme-androidstudio`     | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-androidstudio.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-androidstudio) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-androidstudio.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-androidstudio)                 | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/androidstudio)     |
 | `@uiw/codemirror-theme-atomone`           | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-atomone.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-atomone) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-atomone.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-atomone)                                         | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/atomone)           |
 | `@uiw/codemirror-theme-aura`              | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-aura.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-aura) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-aura.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-aura)                                                     | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/aura)              |
+| `@uiw/codemirror-theme-basic`             | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-basic.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-basic) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-basic.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-basic)                                                 | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/bbedit)            |
 | `@uiw/codemirror-theme-bbedit`            | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-bbedit.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-bbedit) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-bbedit.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-bbedit)                                             | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/bbedit)            |
 | `@uiw/codemirror-theme-bespin`            | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-bespin.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-bespin) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-bespin.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-bespin)                                             | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/bespin)            |
 | `@uiw/codemirror-theme-duotone`           | [![npm version](https://img.shields.io/npm/v/@uiw/codemirror-theme-duotone.svg)](https://www.npmjs.com/package/@uiw/codemirror-theme-duotone) [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/codemirror-theme-duotone.svg?style=flat)](https://www.npmjs.com/package/@uiw/codemirror-theme-duotone)                                         | [`#preview`](https://uiwjs.github.io/react-codemirror/#/theme/data/duotone/light)     |