🤔 图表的左右边距可以去掉么

### 🐛 Question description [Please make everyone to understand it]

想让图表撑满盒子宽度，我该怎么配置呢

### 💻 Link to minimal reproduction

Please provide a link by forking these links [g2plot](https://codesandbox.io/s/g2plot-reproduction-template-gyej1) or GitHub repo. What is a minimal reproduction, and why is it required?

### 🏞 Expected result

不想要这两片空白


### 🚑 Any additional [like screenshots]

* **G2Plot Version**:
* **Platform**:

Start with the linked G2Plot reproduction template and reproduce the chart shown in the screenshot. Determine whether the chart can be configured to fill the container without the two blank side areas; done means the chart spans the box width.

Written by the indexing model from the issue text.