message: fix grammar error in README
diff: ZRender
  =======
  -A lightweight graphic library which providing 2d draw for [Apache ECharts](https://github.com/apache/incubator-echarts).
  +A lightweight graphic library which provides 2d draw for [Apache ECharts](https://github.com/apache/incubator-echarts).
  [![Build Status](https://travis-ci.com/ecomfe/zrender.svg?branch=master)](https://travis-ci.com/ecomfe/zrender) [![](https://img.shields.io/npm/dw/zrender.svg?label=npm%20downloads&style=flat)](https://www.npmjs.com/package/zrender) ![Commits Since 4.0.0](https://img.shields.io/github/commits-since/ecomfe/zrender/4.0.0.svg?colorB=%234c1&style=flat)
  