docs: update readme guideline (#242)

Author: yanglbme

README.md

@@ -47,7 +47,7 @@ Doocs now has the following hot projects:
 
 I believe many of you have a deep understanding that participating in open source projects is very helpful for personal growth. If you love open source or you are curious about it, join Doocs, work with us, maintain our projects and grow together. You can join us in the following two ways:
 
-- Comment on the [relevant issue](https://github.com/doocs/doocs.github.io/issues) on GitHub to express interest in joining the community.
+- Comment on the [relevant discussion](https://github.com/orgs/doocs/discussions/241) on GitHub to express interest in joining the community.
 - Send an email to [admin@doocs.org](mailto:admin@doocs.org?Subject=Join%20the%20Doocs%20Open%20Source%20organization) with the GitHub ID to request to join the community.
 
 By default, your Doocs membership will be hidden from view aftering joining us. If you'd like to display the organization icon in your profile, you can switch from "Private" to "Public" here: https://github.com/orgs/doocs/people. We also recommend setting it to Public.

README_CN.md

@@ -45,7 +45,7 @@ https://doocs.org
 
 如果你热爱开源，或者抱着一颗好奇的心，不妨加入 [Doocs](https://github.com/doocs) 组织，和我们一起维护项目，共同成长。可以通过以下两种方式加入：
 
-- 直接在[此项目](https://github.com/doocs/doocs.github.io)的 [issue](https://github.com/doocs/doocs.github.io/issues/1) 上评论，告知我们你想加入 Doocs。
+- 直接在[此项目](https://github.com/doocs/doocs.github.io)的 [discussion](https://github.com/orgs/doocs/discussions/241) 上评论，告知我们你想加入 Doocs。
 - 发送邮件到 [admin@doocs.org](mailto:admin@doocs.org?Subject=加入Doocs开源组织)，写明你的 GitHub ID，如 [yanglbme](https://github.com/yanglbme)。
 
 默认情况下，在你加入我们之后，你作为 GitHub Doocs 组织成员的信息是处于隐藏状态的。如果你希望在你的个人 GitHub 资料页上展示 Doocs 组织，你可以在此链接 https://github.com/orgs/doocs/people 处将你的信息从 `private` “**私有**”改为 `public` “**公开**”。当然，我们推荐设置为**公开**。