feat: contribution

contribution.md

@@ -0,0 +1,10 @@
+---
+title:  "为 HMCL 帮助文档出一份力"
+permalink: /help/contribution.html
+date:   2021-10-09 23:18:02 +0800
+categories: HMCL
+toc: true
+---
+
+如果你认为你有能力为 HMCL 添加高质量的帮助文档，或希望修改错误，你可以到 https://github.com/huanghongxun/HMCL-docs 仓库中发 Pull Request，或者提 Issue。
+或者你可以进入我们的 [Discord](https://discord.gg/jVvC7HfM6U)、[开黑啦](https://kaihei.co/Kx7n3t)群以向 HMCL 反馈。

multiplayer-symmetric.md

@@ -1,6 +1,6 @@
 ---
 title:  "NAT 网络检测为差的时候怎么办？"
-permalink: /help/launcher/multiplayer/
+permalink: /help/launcher/multiplayer-symmetric.html
 date:   2021-10-09 23:18:02 +0800
 categories: HMCL
 toc: true

multiplayer.md

@@ -1,6 +1,6 @@
 ---
 title:  "多人联机帮助"
-permalink: /help/launcher/multiplayer/
+permalink: /help/launcher/multiplayer.html
 date:   2021-10-09 23:18:02 +0800
 categories: HMCL
 toc: true