dsh-wechat-et: WeChat Communication Etiquette

`dsh-wechat-et` is a DSH plugin designed to provide standardized etiquette guidelines for WeChat communication scenarios. It is implemented in pure Node.js and has no network dependencies, enabling it to instantly return relevant communication suggestions based on input parameters. After developers install it using the official command, they can invoke the related tools in a session to obtain lightweight etiquette assistance, making it suitable for developers who need dynamic suggestions and emphasize security and compliance.