The missing content

This is definitely a well structured and friendly project, however, contents like "web worker", "canvas api", "message channel", etc are missing (or i missed). Is there a plan for additional articles in order to make this project even better ?
if so, I'd like to contribute to "web worker"(or other) section.

首先查看现有教程内容以及 issue 中提出的主题：web workers、Canvas API 和 message channels。范围和目标文章尚未确定；要视为完成，需要达成主题共识，并完成一篇整合到教程中的文章。

由索引模型根据 Issue 内容生成。