Add Sip guidelines

# Basic guidelines for formatting a Gulp Sips Series article

## Article Structure
Title
Large Image (replaces 55 words)
Series Description as shown: This is part of our Gulp Sips series: bringing you easily-digestible bits of information on our advanced or unknown features.
Body (can be What?, How?, Why?)

Notes:
* No more than 200 words/2 minute read, including images. This is based on the Medium’s basic time calculations.
* Add a cmd + enter between each titled section
* To add code to Medium
* Block code: add ```before your code
* To add inline code, type your code, highlight it, then click ` (a single tick).

未指定文件或入口点。首先定位仓库中现有的 Gulp Sips 或文章指导内容，然后添加所列结构和 Medium 格式规则，并验证最终的指导涵盖每项要求。

由索引模型根据 Issue 内容生成。